Solar tracking systems, as well as methods of using such solar tracking systems, are disclosed. More particularly, embodiments of the solar tracking systems include lateral supports horizontally positioned between uprights to support photovoltaic modules. The lateral supports may be raised and lowered along the uprights or translated to cause the photovoltaic modules to track the moving sun.

Solar ADEPT Project: The 7 projects that make up ARPA-E's Solar ADEPT program, short for 'Solar Agile Delivery of Electrical Power Technology,' aim to improve the performance of photovoltaic (PV) solar energy systems, which convert the sun's rays into electricity. Solar ADEPT projects are integrating advanced electrical components into PV systems to make the process of converting solar energy to electricity more efficient.

A fault detecting apparatus and method are provided for use with an active solarsystem. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solarsystem. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solarsystem and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solarsystem are increased.

A fault detecting apparatus and method are provided for use with an active solarsystem. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solarsystem. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solarsystem and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solarsystem are increased.

A solar energy collection system for a building is described. A solar energy collector is disposed at the exterior surface of the building and includes a solar energy absorbent body having a surface which is exposed to sunlight and from which solar energy can be transmitted as sensible heat. A panel which is transparent to sunlight is spaced from the said surface of the absorbent body so as to define therewith a passageway in which air contacts at least a substantial area of said surface so that air in said passageway absorbs heat transmitted from said surface when the collector is in use. The passageway has an inlet and an outlet and the absorbent body and panel are arranged with the outlet higher than the inlet so that heated air in the passageway tends to rise by convection towards the outlet. The building is provided with heating means including a circulation circuit for a heating fluid. Heat exchange means are coupled to said air passageway outlet of the solar energy collector for passage of heated air therethrough. The heat exchange means are also coupled to the circulation circuit of the building heating means and are arranged to permit heat transfer between said heated air and the heating fluid. A return air flow conduit is coupled between the heat exchange means and the inlet of the air passageway of the solar energy collector for returning heated air from the heat exchange means to the air passageway for recirculation.

A solar thermal power generator includes an inclined elongated boiler tube positioned in the focus of a solar concentrator for generating steam from water. The boiler tube is connected at one end to receive water from a pressure vessel as well as connected at an opposite end to return steam back to the vessel in a fluidic circuit arrangement that stores energy in the form of heated water in the pressure vessel. An expander, condenser, and reservoir are also connected in series to respectively produce work using the steam passed either directly (above a water line in the vessel) or indirectly (below a water line in the vessel) through the pressure vessel, condense the expanded steam, and collect the condensed water. The reservoir also supplies the collected water back to the pressure vessel at the end of a diurnal cycle when the vessel is sufficiently depressurized, so that the system is reset to repeat the cycle the following day. The circuital arrangement of the boiler tube and the pressure vessel operates to dampen flow instabilities in the boiler tube, damp out the effects of solar transients, and provide thermal energy storage which enables time shifting of power generation to better align with the higher demand for energy during peak energy usage periods.

An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.

An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

This fact sheet describes an integrated solar thermochemical reaction system project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by the Pacific Northwest National Laboratory, is working to develop and demonstrate a high-performance solar thermochemical reaction system in an end-to-end demonstration that produces electricity. A highly efficient solar thermochemical reaction system would allow for 24-hour operation without the need for storage technology, and reductions in total system costs while providing a relatively low-risk deployment option for CSP systems.

Views of the SolarSystem has been created as an educational tour of the solarsystem. It contains images and information about the Sun, planets, moons, asteroids and comets found within the solarsystem. The image processing for many of the images was done by the author. This tour uses hypertext to allow space travel by simply clicking on a desired planet. This causes information and images about the planet to appear on screen. While on a planet page, hyperlinks travel to pages about the moons and other relevant available resources. Unusual terms are linked to and defined in the Glossary page. Statistical information of the planets and satellites can be browsed through lists sorted by name, radius and distance. History of Space Exploration contains information about rocket history, early astronauts, space missions, spacecraft and detailed chronology tables of space exploration. The Table of Contents page has links to all of the various pages within Views Of the SolarSystem.

A solar-powered adsorption-desorption refrigeration and air conditioning system uses nanostructural materials made of high specific surface area adsorption aerogel as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material. A circulation system circulates refrigerant from the nanostructural material to a cooling unit.

This paper presents results on a highly efficient experimental solar thermophotovoltaic (STPV) system using simulated solar energy. An overall power conversion efficiency of 6.2% was recorded under solar simulation. This was matched with a thermodynamic model, and the losses within the system, as well as a path forward to mitigate these losses, have been investigated. The system consists of a planar, tungsten absorbing/emitting structure with an anti-reflection layer coated laser-microtextured absorbing surface and single-layer dielectric coated emitting surface. A GaSb PV cell was used to capture the emitted radiation and convert it into electrical energy. This simple structure is bothmore »easy to fabricate and temperature stable, and contains no moving parts or heat exchange fluids.« less

Buying & Making Electricity Â» Small Solar Electric Systems Small Solar Electric Systems A small solar electric or photovoltaic system can be a reliable and pollution-free producer of electricity for your home or office. A small solar electric or photovoltaic (PV) system can be a reliable and pollution-free producer of electricity for your home or office. Small PV systems also provide a cost-effective power supply in locations where it is expensive or impossible to send electricity through

An adaptive full spectrum solar energy system having at least one hybrid solar concentrator, at least one hybrid luminaire, at least one hybrid photobioreactor, and a light distribution system operably connected to each hybrid solar concentrator, each hybrid luminaire, and each hybrid photobioreactor. A lighting control system operates each component.

A system for generating electrical power from sunlight, comprises a focussing diffraction grating or other focussing, spectrally dispersive means and a photocell array. The diffraction grating focuses sunlight into a spectrally dispersed band. The photocell array is composed of cells with different spectral sensitivities, located in positions in the dispersed band corresponding to the cell spectral sensitivities so that the net conversion efficiency of sunlight to electricity exceeds the conversion efficiency attainable with nondispersive collectors and single material photocells. Alternate embodiments of the invention provide sun tracking means, reflective or transmissive diffraction gratings, flat or curved diffraction grating surfaces , on- or off-axis focus, and optical coatings on the photocell surfaces.

A solar-powered adsorption-desorption refrigeration and air conditioning system that uses nanostructural materials such as aerogels, zeolites, and sol gels as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material while the material is at a relatively low temperature, perhaps at night. During daylight hours, when the nanostructural materials is heated by the sun, the refrigerant are thermally desorbed from the surface of the aerogel, thereby creating a pressurized gas phase in the vessel that contains the aerogel. This solar-driven pressurization forces the heated gaseous refrigerant through a condenser, followed by an expansion valve. In the condenser, heat is removed from the refrigerant, first by circulating air or water. Eventually, the cooled gaseous refrigerant expands isenthalpically through a throttle valve into an evaporator, in a fashion similar to that in more conventional vapor recompression systems.

Department of Energy Integrated Solar Thermochemical Reaction System Project Profile: Integrated Solar Thermochemical Reaction System PNNL logo Pacific Northwest National Laboratory, under the 2012 SunShot Concentrating Solar Power (CSP) R&D funding opportunity announcement (FOA), is creating a new CSP method for hybridization with fossil-fuel plants. The system uses solar energy to drive a chemical reaction that produces a gas capable of offsetting the need for fossil fuels in

A hybrid solar lighting distribution system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates all components.

A hybrid solar lighting system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates each component.

A tracking system is provided for pivotally mounted spaced-apart solar collectors. A pair of cables is connected to spaced-apart portions of each collector, and a driver displaces the cables, thereby causing the collectors to pivot about their mounting, so as to assume the desired orientation. The collectors may be of the cylindrical type as well as the flat-plate type. Rigid spar-like linkages may be substituted for the cables. Releasable attachments of the cables to the collectors is also described, as is a fine tuning mechanism for precisely aligning each individual collector.

A tracking system is provided for pivotally mounted spaced-apart solar collectors. A pair of cables is connected to spaced-apart portions of each collector, and a driver displaces the cables, thereby causing the collectors to pivot about their mounting, so as to assume the desired orientation. The collectors may be of the cylindrical type as well as the flat-plate type. Rigid spar-like linkages may be substituted for the cables. Releasable attachments of the cables to the collectors is also described, as is a fine tuning mechanism for precisely aligning each individual collector.

A solar energy electric generating system is described comprising in combination: (a) an array of photocells; (b) means for gating the electrical direct current energy produced by the array of photocells; (c) means for transforming the electrical direct current energy at an output of the array of photocells whereby an alternating current at the output of the transforming means is produced, and which is controlled by a control device for controlling the rate and duty cycle of the gating means; and (d) a photosensitive sampler which samples light incident upon the photocell array and outputs a proportional signal.

A central focus solar energy system consists of one or more arrays of mirrors, a receiver for each array, a sun tracker, a sun tracker sun acquisition device and a control unit. Mirrors of the arrays are subjected to two-axis control by electromechanical devices actuated by sun-tracking error signals generated by the sun tracker. Mirrors are thus oriented so as to cause reflections of the direct rays of the sun from all mirrors in an array to converge on a receiver at a common focus. Fixed (Principal) axes of mirror rotation are parallel to the fixed (Principal) axis of rotation of the sun tracker sensor making orientation of the system independent of the earth's spin axis. The system includes a ''vernier'' or fine adjustment control for positioning mirrors that supplements sun tracker controls.

The work accomplished by the Aerospace Corporation from April 1973 through November 1979 in the mission analysis of solar thermal power systems is summarized. Sponsorship of this effort was initiated by the National Science Foundation, continued by the Energy Research and Development Administration, and most recently directed by the United States Department of Energy, Division of Solar Thermal Systems. Major findings and conclusions are sumarized for large power systems, small power systems, solar total energy systems, and solar irrigation systems, as well as special studies in the areas of energy storage, industrial process heat, and solar fuels and chemicals. The various data bases and computer programs utilized in these studies are described, and tables are provided listing financial and solar cost assumptions for each study. An extensive bibliography is included to facilitate review of specific study results and methodology.

The solar energy available within the visible portion of the solar spectrum is about 300 W/m2 (43%) and that available in the UV and IR portion is about 400 W/m2 (57%). This provides opportunities for developing integrated energy systems that capture and use specific wavelengths of the solar spectrum for different purposes. For example: biofuels from photosynthetic microbes use only the visible light; solar cells use a narrow band of the solar spectrum that could be either mostly in the visible or in the IR regions of the solar spectrum, depending on the photovoltaic materials, e.g., gallium antimonide (GaSb) cells utilize predominately IR radiation; and finally, solar panels that heat water utilize a broad range of wavelengths (visible plus IR). The basic idea of this research is that sunlight has many possible end-use applications including both direct use and energy conversion schemes; it is technically feasible to develop multifunctional solar energy systems capable of addressing several end-use needs while increasing the overall solar energy utilization efficiency when compared to single-purpose solar technologies. Such a combination of technologies could lead to more cost-competitive ?multifunctional? systems that add value and broaden opportunities for integrated energy systems. The goal of this research is to increase the overall energy efficacy and cost competitiveness of solarsystems. The specific objectives of this research were: 1) Evaluate the efficacy of a combined photobioreactor and electric power system; 2) Improve the reliability and cost effectiveness of hybrid solar lighting systems ? a technology in which sunlight is collected and distributed via optical fibers into the interior of a building; 3) Evaluate the efficacy of using filtered light to increase the production of biomass in photobioreactors and provide more solar energy for other uses; 4) Evaluates several concepts for wavelength shifting such that a greater percentage of the solar

Department of Energy Highly Efficient Solar Thermochemical Reaction Systems Webinar: Highly Efficient Solar Thermochemical Reaction Systems Below is the text version of the webinar titled "Highly Efficient Solar Thermochemical Reaction Systems," originally presented on January 13, 2015. In addition to this text version of the audio, you can access the presentation slides. Amit Talapatra: Hello, everyone, and thanks for joining today's webinar. Today's webinar is being recorded, so

Studying the SolarSystem's Chemical Recipe Studying the SolarSystem's Chemical Recipe Print Tuesday, 26 March 2013 00:00 To study the origins of different isotope ratios among the elements that make up today's smorgasbord of planets, moons, comets, asteroids, and interplanetary ice and dust, a team of scientists from the University of California, San Diego is using ALS Chemical Dynamics Beamline 9.0.2 to mimic radiation from the protosun when the solarsystem was forming. For more than three

A solar thermal collector system is described one of a class of devices which converts solar radiation into heat and transmits this heat to storage from whence it is utilized, comprising: an evacuated glass solar collector, the evacuated glass solar collector having a glass vacuum envelope, the upper portion of the glass vacuum envelope also serving as window to pass solar radiation, the evacuated glass solar collector having a multiplicity of substantially parallel linear adjacent concentrating troughs, each trough shaped and mirror surfaced so as concentrate solar radiation in the vacuum, the mirror surface inside the vacuum and the concentration approximately ideal, the multiplicity of substantially parallel linear adjacent troughs extending substantially over the entire length and width of the evacuated glass solar collector; a heat storage system, the heat storage system adjacent to the evacuated glass solar collector, the heat storage system having a heat storage tank which is thermally insulated, the heat storage tank containing a heat storage medium, and the heat storage system including means of removal of heat from the heat storage tank for utilization.

The staff of the Southwest Technology Development Institute (SWTDI), in conjunction with the staff of Industrial Solar Technology (IST), have analyzed the performance, operation, and maintenance of a large solar process heat system in use at the 5,000 inmate California Correctional Institution (CCI) in Tehachapi, CA. This report summarizes the key design features of the solar plant, its construction and maintenance histories through the end of 1991, and the performance data collected at the plant by a dedicated on-site data acquisition system (DAS).

Studying the SolarSystem's Chemical Recipe Print To study the origins of different isotope ratios among the elements that make up today's smorgasbord of planets, moons, comets, asteroids, and interplanetary ice and dust, a team of scientists from the University of California, San Diego is using ALS Chemical Dynamics Beamline 9.0.2 to mimic radiation from the protosun when the solarsystem was forming. For more than three decades, Mark Thiemens, Dean of the Division of Physical Sciences at UCSD,

Studying the SolarSystem's Chemical Recipe Print To study the origins of different isotope ratios among the elements that make up today's smorgasbord of planets, moons, comets, asteroids, and interplanetary ice and dust, a team of scientists from the University of California, San Diego is using ALS Chemical Dynamics Beamline 9.0.2 to mimic radiation from the protosun when the solarsystem was forming. For more than three decades, Mark Thiemens, Dean of the Division of Physical Sciences at UCSD,

Studying the SolarSystem's Chemical Recipe Print To study the origins of different isotope ratios among the elements that make up today's smorgasbord of planets, moons, comets, asteroids, and interplanetary ice and dust, a team of scientists from the University of California, San Diego is using ALS Chemical Dynamics Beamline 9.0.2 to mimic radiation from the protosun when the solarsystem was forming. For more than three decades, Mark Thiemens, Dean of the Division of Physical Sciences at UCSD,

Studying the SolarSystem's Chemical Recipe Print To study the origins of different isotope ratios among the elements that make up today's smorgasbord of planets, moons, comets, asteroids, and interplanetary ice and dust, a team of scientists from the University of California, San Diego is using ALS Chemical Dynamics Beamline 9.0.2 to mimic radiation from the protosun when the solarsystem was forming. For more than three decades, Mark Thiemens, Dean of the Division of Physical Sciences at UCSD,

Exchangers for Solar Water Heating Systems Heat Exchangers for Solar Water Heating Systems Image of a heat exchanger. | Photo from iStockphoto.com Image of a heat exchanger. | Photo from iStockphoto.com Solar water heating systems use heat exchangers to transfer solar energy absorbed in solar collectors to the liquid or air used to heat water or a space. Heat exchangers can be made of steel, copper, bronze, stainless steel, aluminum, or cast iron. Solar heating systems usually use copper,

Today's solar technologies are more efficient and versatile than ever before, adding to the appeal of an already desirable energy source. This fact sheet provides information on the basics of a solar electric system, including components of a system, how to choose solar modules, and how to choose a solarsystem.

The operation and uses of solar cells and the National Photovoltaic Program are briefly described. Eleven DOE photovoltaic application projects are described including forest lookout towers; Wilcox Memorial Hospital in Hawaii; WBNO daytime AM radio station; Schuchuli Indian Village; Meade, Nebraska, agricultural experiment; Mt. Laguna Air Force Station; public schools and colleges; residential applications; and Sea World of Florida. (WHK)

A solar energy system including a pedestal defining a longitudinal axis, a frame that is supported by the pedestal and that is rotateable relative to the pedestal about the longitudinal axis, the frame including at least one solar device, and a wind vane operatively connected to the frame to urge the frame relative to the pedestal about the longitudinal axis in response to wind acting on the wind vane.

Electrical power generated with the heat from the sun, called solar thermal power, is produced with three types of concentrating solarsystems - trough or line-focus systems; power towers in which a centrally-located thermal receiver is illuminated with a large field of sun-tracking heliostats; and dish/engine systems. A special case of the third type of system, a dish/Stirling system, is the subject of this paper. A dish/Stirling system comprises a parabolic dish concentrator, a thermal receiver, and a Stirling engine/generator located at the focus of the dish. Several different dish/Stirling systems have been built and operated during the past 15 years. One system claims the world record for net conversion of solar energy to electric power of 29.4%; and two different company`s systems have accumulated thousands of hours of on-sun operation. Due to de-regulation and intense competition in global energy markets as well as the immaturity of the technology, dish/Stirling systems have not yet found their way into the marketplace. This situation is changing as solar technologies become more mature and manufacturers identify high-value niche markets for their products. In this paper, I review the history of dish/Stirling system development with an emphasis on technical and other issues that directly impact the Stirling engine. I also try to provide some insight to the opportunities and barriers confronting the application of dish/Stirling in power generation markets.

A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

Home Solar Electric System Planning a Home Solar Electric System Whether a home solar electric system will work for you depends on the available sun (resource), available space for the system size you need, the economics of the investment, and the local permits required. | Photo courtesy of Decker Homes. Whether a home solar electric system will work for you depends on the available sun (resource), available space for the system size you need, the economics of the investment, and the local

The Permit Application Checklist is intended to be used as a best management practice when establishing local government requirements for residential and commercial solar photovoltaic (PV) system permits. Local governments may modify this checklist to accommodate their local ordinances, code requirements, and permit procedures.

Rooftop Solar Electric System at Sunset Rooftop Solar Electric System at Sunset Rooftop Solar Electric System at Sunset In this photograph, a worker inspects the photovoltaic electric array, which is made of SunPower PowerGuard system. SunPower is an industry partner with the U.S. Department of Energy Solar Energy Technologies Program. High Resolution JPG (3.31 MB) More Documents & Publications Rooftop Solar Electric System at Sunset Solar Array on Portland Water Bureau Meter Shop Rooftop

The author discusses the issue of providing solar home systems to primarily rural areas from the perspective of how to commercialize the process. He considers two different approaches, one an open market approach and the other an exclusive market approach. He describes examples of the exclusive market approach which are in process in Argentina and Brazil. Coming from a banking background, the business aspects are discussed in detail. He points out the strengths and weaknesses of both approaches toward developing such systems.

Energy Solar Power Conversion System Project Profile: Brayton Solar Power Conversion System Brayton Energy logo Brayton Energy, under the CSP R&D FOA, is looking to demonstrate the viability and economics of a new concentrating solar thermal power conversion system. Approach An image of a 320-square-meter dish with Brayton Energy's power conversion module and a 200-kWe turboalternator and solar receiver. The project focuses on designing and testing the power conversion system and

of Energy Codes and Regulations for Solar Water Heating Systems Building Codes and Regulations for Solar Water Heating Systems Photo Credit: iStockphoto Photo Credit: iStockphoto Before installing a solar water heating system, you should investigate local building codes, zoning ordinances, and subdivision covenants, as well as any special regulations pertaining to the site. You will probably need a building permit to install a solar energy system onto an existing building. Not every

This paper presents a thermal model that describes the performance of solar absorption HVAC systems. The model considers the collector array, the building cooling and heating loads, the absorption chiller and the high temperature storage. Heat losses from the storage tank and piping are included in the model. All of the results presented in the paper are for an array of flat plate solar collectors with black chrome (selective surface) absorber plates. The collector efficiency equation is used to calculate the useful heat output from the array. The storage is modeled as a non-stratified tank with polyurethane foam insulation. The system is assumed to operate continuously providing air conditioning during the cooling season, space heating during the winter and hot water throughout the year. The amount of heat required to drive the chiller is determined from the coefficient of performance of the absorption cycle. Results are presented for a typical COP of 0.7. The cooling capacity of the chiller is a function of storage (generator) temperature. The nominal value is 190 F (88 C) and the range of values considered is 180 F (82 C) to 210 F (99 C). Typical building cooling and heating loads are determined as a function of ambient conditions. Performance results are presented for Sacramento, CA and Washington, D.C. The model described in the paper makes use of National Solar Radiation Data Base (NSRDB) data and results are presented for these two locations. The uncertainties in the NSRDB are estimated to be in a range of 6% to 9%. This is a significant improvement over previously available data. The model makes it possible to predict the performance of solar HVAC systems and calculate quantities such as solar fraction, storage temperature, heat losses and parasitic power for every hour of the period for which data are available.

The Energy Department will present a live webinar titled "Potential Strategies for Integrating Solar Hydrogen Production and Concentrating Solar Power: A Systems Analysis" on Thursday, January 21, from 12 to 1 p.m. Eastern Standard Time (EST).

Access the recording and download the presentation slides from the Fuel Cell Technologies Office webinar "Potential Strategies for Integrating Solar Hydrogen Production and Concentrating Solar Power: A Systems Analysis" held on January 21, 2016.

An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

County, CA | Department of Energy 6: Ivanpah Solar Electric Generating System in San Bernardino County, CA EIS-0416: Ivanpah Solar Electric Generating System in San Bernardino County, CA Documents Available for Download October 22, 2010 EIS-0416: EPA Notice of Availability of the Final Environmental Impact Statement Ivanpah Solar Electric Generating System (07-AFC-5) Project, Proposal to Construct a 400-m Megawatt Concentrated Solar Power Tower, Thermal-Electric Power Plant, San Bernardino

Energy Concentrating Solar Power Thermal Storage System Basics Concentrating Solar Power Thermal Storage System Basics August 21, 2013 - 10:33am Addthis One challenge facing the widespread use of solar energy is reduced or curtailed energy production when the sun sets or is blocked by clouds. Thermal energy storage provides a workable solution to this challenge. In a concentrating solar power (CSP) system, the sun's rays are reflected onto a receiver, which creates heat that is used to

Production of Electricity | Department of Energy Integrated Solar Thermochemical Reaction System for High Efficiency Production of Electricity Integrated Solar Thermochemical Reaction System for High Efficiency Production of Electricity This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23-25, 2013 near Phoenix, Arizona. csp_review_meeting_042313_wegeng.pdf (2.22 MB) More Documents & Publications Highly Efficient Solar

This paper presents energy performance of 12 passive solarsystems for three climatically different zones of Bulgaria. The results are compared with a base-case residential house that has a design typical for these areas. The different passive solarsystems are compared on the basis of the percentage of solar savings and the yield, which is the annual net benefit of adding the passive solarsystem. The analyses are provided based on monthly meteorological data, and the method used for calculations is the Solar Load Ratio. Recommendations for Bulgarian conditions are given. 5 refs., 4 figs., 1 tab.

Buying & Making Electricity Â» Hybrid Wind and Solar Electric Systems Hybrid Wind and Solar Electric Systems Because the peak operating times for wind and solarsystems occur at different times of the day and year, hybrid systems are more likely to produce power when you need it. Because the peak operating times for wind and solarsystems occur at different times of the day and year, hybrid systems are more likely to produce power when you need it. According to many renewable energy experts,

A parabolic-trough solar collector system is disclosed, with each collector driven to track the sun using a ring driven in centerless fashion. The parabolic troughs are made of laminated plywood or molded or formed of plastics or metals. The drive motor moves a flexible belt, i.e., chain or cable, which is routed about the drive ring on each collector. The motion of the cable moves all drive rings together to track the sun. A photodetector senses the position of the sun and provides the signal needed to drive the collectors in the correct direction.

Several major conceptual design studies of solar central receiver systems and components have been completed in the last year. The results of these studies are used to compare the projected cost of electric power generation using central receiver systems with that of more conventional power generation. The cost estimate for a molten salt central receiver system is given. Levelized busbar energy cost is shown as a function of annual capacity factor indicating the fraction of the cost due to each of the subsystems. The estimated levelized busbar energy cost for a central receiver (70 to 90 mills per kilowatt hour) is compared with the levelized busbar energy cost for a new coal fired Rankine cycle plant. Sensitivities to the initial cost of coal and the delta fuel escalation are shown. (WHK)

Experience with a large number of installed solar energy systems in the HUD Solar Program has shown that a variety of problems and design/installation errors have occurred in many solarsystems, sometimes resulting in substantial additional costs for repair and/or replacement. In this paper, the effect of problems and errors on the economics of solar energy systems is examined. A method is outlined for doing this in terms of selected economic indicators. The method is illustrated by a simple example of a residential solar DHW system. An example of an installed, instrumented solar energy system in the HUD Solar Program is then discussed. Detailed results are given for the effects of the problems and errors on the cash flow, cost of delivered heat, discounted payback period, and life-cycle cost of the solar energy system. Conclusions are drawn regarding the most suitable economic indicators for showing the effects of problems and errors in solar energy systems. A method is outlined for deciding on the maximum justifiable expenditure for maintenance on a solar energy system with problems or errors.

Department of Energy Everything You Wanted to Know About Solar Water Heating Systems Everything You Wanted to Know About Solar Water Heating Systems October 7, 2014 - 2:39pm Q&A What do you want to know about solar at home? Tell Us Addthis Solar panels heat water that is delivered to a storage tank. | Photo courtesy of David Springer, National Renewable Energy Laboratory Solar panels heat water that is delivered to a storage tank. | Photo courtesy of David Springer, National Renewable

Under the 10{sup th} Malaysian Plan, the government is expecting the renewable energy to contribute approximately 5.5% to the total electricity generation by the year 2015, which amounts to 98MW. One of the initiatives to ensure that the target is achievable was to establish the Sustainable Energy Development Authority of Malaysia. SEDA is given the authority to administer and manage the implementation of the feed-in tariff (FiT) mechanism which is mandated under the Renewable Energy Act 2011. The move to establish SEDA is commendable and the FiT seems to be attractive but there is a need to create awareness on the implementation of the solar electricity generating system (SEGS). In Malaysia, harnessing technologies related to solar energy resources have great potential for implementation. However, the main issue that plagues the implementation of SEGS is the intermittent nature of this source of energy. The availability of sunlight is during the day time, and there is a need for electrical energy storage system, so that there is electricity available during the night time as well. The meteorological condition such as clouds, haze and pollution affects the SEGS as well. The PV based SEGS is seems to be promising electricity generating system that can contribute towards achieving the 5.5% target and will be able to minimize the negative effects of utilizing fossil fuels for electricity generation on the environment. Malaysia is committed to Kyoto Protocol, which emphasizes on fighting global warming by achieving stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. In this paper, the technical aspects of the implementation of optimum SEGS is discussed, especially pertaining to the positioning of the PV panels.

This book presents the papers given at a conference sponsored by the US DOE, the Solar Energy Research Institute, SolarVision, Inc., and the Southern California Solar Energy Society. The topics considered at the conference included sizing solar energy systems for agricultural applications, a farm scale ethanol production plant, the EEC wind energy RandD program, the passive solar performance assessment of an earth-sheltered house, the ARCO 1 MW photovoltaic power plant, the performance of a dendritic web photovoltaic module, second generation point focused concentrators, linear fresnel lens concentrating photovoltaic collectors, photovoltaic conversion efficiency, amorphous silicon thin film solar cells, a photovoltaic system for a shopping center, photovoltaic power generation for the utility industry, spectral solar radiation, and the analysis of insolation data.

Solar Water Heaters Â» Heat Transfer Fluids for Solar Water Heating Systems Heat Transfer Fluids for Solar Water Heating Systems Illustration of a solar water heater. Illustration of a solar water heater. Heat-transfer fluids carry heat through solar collectors and a heat exchanger to the heat storage tanks in solar water heating systems. When selecting a heat-transfer fluid, you and your solar heating contractor should consider the following criteria: Coefficient of expansion - the fractional

The inevitable transformation of the electrical grid to a more distributed generation configuration requires solarsystem capabilities well beyond simple net-metered, grid-connected approaches. Time-of-use and peak-demand rate structures will require more sophisticated systems designs that integrate energy management and/or energy storage into the system architecture. Controlling power flow into and from the utility grid will be required to ensure grid reliability and power quality. Alternative protection strategies will also be required to accommodate large numbers of distributed energy sources. This document provides an overview of the R&D needs and describes some pathways to promising solutions. The solutions will, in many cases, require R&D of new components, innovative inverter/controllers, energy management systems, innovative energy storage and a suite of advanced control algorithms, technical methodologies, protocols and the associated communications. It is expected that these solutions will help to push the âadvanced integrated systemâ and âsmart gridâ evolutionary processes forward in a faster but focused manner.

The field of exoplanetary science has experienced a recent surge of new systems that is largely due to the precision photometry provided by the Kepler mission. The latest discoveries have included compact planetary systems in which the orbits of the planets all lie relatively close to the host star, which presents interesting challenges in terms of formation and dynamical evolution. The compact exoplanetary systems are analogous to the moons orbiting the giant planets in our solarsystem, in terms of their relative sizes and semimajor axes. We present a study that quantifies the scaled sizes and separations of the solarsystem moons with respect to their hosts. We perform a similar study for a large sample of confirmed Kepler planets in multi-planet systems. We show that a comparison between the two samples leads to a similar correlation between their scaled sizes and separation distributions. The different gradients of the correlations may be indicative of differences in the formation and/or long-term dynamics of moon and planetary systems.

This document introduces the Energy Department's new Guide to Community Shared Solar: Utility, Private, and Nonprofit Project Development. The guide is designed to help those who want to develop community shared solar projects - from community organizers and advocates to utility managers and government officials - navigate the process of developing shared systems, from early planning to implementation.

Embodiments described herein relate to a method of producing energy from concentrated solar flux. The method includes dropping granular solid particles through a solar flux receiver configured to transfer energy from concentrated solar flux incident on the solar flux receiver to the granular solid particles as heat. The method also includes fluidizing the granular solid particles from the solar flux receiver to produce a gas-solid fluid. The gas-solid fluid is passed through a heat exchanger to transfer heat from the solid particles in the gas-solid fluid to a working fluid. The granular solid particles are extracted from the gas-solid fluid such that the granular solid particles can be dropped through the solar flux receiver again.

This study develops a systematic framework for estimating the increase in operating costs due to uncertainty and variability in renewable resources, uses the framework to quantify the integration costs associated with sub-hourly solar power variability and uncertainty, and shows how changes in system operations may affect these costs. Toward this end, we present a statistical method for estimating the required balancing reserves to maintain system reliability along with a model for commitment and dispatch of the portfolio of thermal and renewable resources at different stages of system operations. We estimate the costs of sub-hourly solar variability, short-term forecast errors, and day-ahead (DA) forecast errors as the difference in production costs between a case with ârealisticâ PV (i.e., subhourly solar variability and uncertainty are fully included in the modeling) and a case with âwell behavedâ PV (i.e., PV is assumed to have no sub-hourly variability and can be perfectly forecasted). In addition, we highlight current practices that allow utilities to compensate for the issues encountered at the sub-hourly time frame with increased levels of PV penetration. In this analysis we use the analytical framework to simulate utility operations with increasing deployment of PV in a case study of Arizona Public Service Company (APS), a utility in the southwestern United States. In our analysis, we focus on three processes that are important in understanding the management of PV variability and uncertainty in power system operations. First, we represent the decisions made the day before the operating day through a DA commitment model that relies on imperfect DA forecasts of load and wind as well as PV generation. Second, we represent the decisions made by schedulers in the operating day through hour-ahead (HA) scheduling. Peaking units can be committed or decommitted in the HA schedules and online units can be redispatched using forecasts that are improved

A compression module may comprise a hermetic helical screw rotary compressor having injection and ejection ports in addition to discharge and suction ports or may comprise a multiple cylinder, multiple level, reciprocating compressor. The module incorporates a subcooler coil and is connected to an outside air coil, a thermal energy storage coil, a direct solar energy supply coil, one or more inside coils for the space to be conditioned and a hot water coil through common, discharge manifold, suction manifold, liquid drain manifold and liquid feed manifold, by suitable solenoid operated control valves and check valves. The solenoid operated control valves are selectively operated in response to system operating parameters. Seal pots and positive displacement pumps may operate to force liquid refrigerant condensed at intermediate pressure to flow to the receiver which is pressurized at a pressure corresponding to the condensation temperature of the highest pressure condensing coil in the system. Alternatively, liquid refrigerant expansion may be used to reach a common receiver pressure for all condenser returns.

Energy Home Solar Electric System Installing and Maintaining a Home Solar Electric System When choosing a contractor, ask about their work record, experience, and licenses, and get more than one bid for the installation of your PV system. | Photo courtesy of Dennis Schroeder, NREL. When choosing a contractor, ask about their work record, experience, and licenses, and get more than one bid for the installation of your PV system. | Photo courtesy of Dennis Schroeder, NREL. Making sure your

This document is the Final Report of the Solar Energy System located at Troy-Miami County Public Library, Troy, Ohio. The completed system is composed of tree basic subsystems: the collector system consisting of 3264 square feet of Owens Illinois evacuated glass tube collectors; the storage system which includes a 5000-gallon insulated steel tank; and the distribution and control system which includes piping, pumping and control logic for the efficient and safe operation of the entire system. This solar heating system was installed in an existing facility and is, therefore, a retrofit system. This report includes extracts from the site files, specifications, drawings, installation, operation and maintenance instructions.

Solar-aided upgrade of the energy content of fossil fuels, such as natural gas, can provide a near-term transition path towards a future solar-fuel economy and reduce carbon dioxide emission from fossil fuel consumption. Both steam and dry reforming a methane-containing fuel stream have been studied with concentrated solar power as the energy input to drive the highly endothermic reactions but the concept has not been demonstrated at a commercial scale. Under a current project with the U.S. Department of Energy, PNNL is developing an integrated solar thermochemical reaction system that combines solar concentrators with micro- and meso-channel reactors and heat exchangers to accomplish more than 20% solar augment of methane higher heating value. The objective of our three-year project is to develop and prepare for commercialization such solar reforming system with a high enough efficiency to serve as the frontend of a conventional natural gas (or biogas) combined cycle power plant, producing power with a levelized cost of electricity less than 6Âą/kWh, without subsidies, by the year 2020. In this paper, we present results from the first year of our project that demonstrated a solar-to-chemical energy conversion efficiency as high as 69% with a prototype reaction system.

Solar-aided upgrade of the energy content of fossil fuels, such as natural gas, can provide a near-term transition path towards a future solar-fuel economy and reduce carbon dioxide emission from fossil fuel consumption. Both steam and dry reforming a methane-containing fuel stream have been studied with concentrated solar power as the energy input to drive the highly endothermic reactions but the concept has not been demonstrated at a commercial scale. Under a current project with the U.S. Department of Energy, PNNL is developing an integrated solar thermochemical reaction system that combines solar concentrators with micro- and meso-channel reactors and heatmoreÂ Â» exchangers to accomplish more than 20% solar augment of methane higher heating value. The objective of our three-year project is to develop and prepare for commercialization such solar reforming system with a high enough efficiency to serve as the frontend of a conventional natural gas (or biogas) combined cycle power plant, producing power with a levelized cost of electricity less than 6Âą/kWh, without subsidies, by the year 2020. In this paper, we present results from the first year of our project that demonstrated a solar-to-chemical energy conversion efficiency as high as 69% with a prototype reaction system.Â«Â less

A study is made of a solar energy system for space heating a 97,000-square-foot office, factory, and warehouse building owned by Telex Communications, Inc. in Blue Earth, Minnesota. The solarsystem has 11,520 square feet of ground-oriented flat-plate collectors and a 20,000-gallon storage tank inside the building. Freeze protection is by drainback. Solar heated water from the storage tank circulates around the clock throughout the heating season to heating coils in the ducts. The system achieves its design solar fraction, is efficient, and generally reliable, but not cost-effective. Performance data for the solarsystem was collected by the National Solar Data Network for three heating seasons from 1978 to 1981. Because of a freeze-up of the collector array in December 1978, the solarsystem was only partially operational in the 1978 to 1979 heating season. The data in this report were collected in the 1979 to 1980 and 1980 to 1981 heating seasons.

The bidirectional solar-optical properties of a fenestration system are necessary to accurately determine its luminous and thermal performance. Bidirectional transmittance and reflectance can be determined experimentally for fenestration systems of arbitrary complexity using a scanning radiometer, after which the total directional absorptance can be calculated. However, for the case of multilayer fenestration systems, this approach does not provide information about the net absorptance of each layer. Moreover, the same layers can be ordered in more than one way, resulting in fenestration systems with different solar-optical properties, the determination which requires additional experimental procedures. This paper describes a mathematical model for the calculation of the bidirectional solar-optical properties of multi-layer fenestration systems, using the bidirectional solar-optical properties of each layer. The model is based on the representation of the bidirectional solar-optical properties using matrices. Matrix operations are then used to calculate the bidirectional solar-optical properties of any combination of layers, considering the interreflections between them. This approach offers two advantages: (1) the reduction of the experimental procedures to those required for the determination of the bidirectional transmittance and reflectance of fenestration layers, rather than complete fenestration systems, and (2) the determination of the net absorptance of each layer as part of the fenestration system, rather than the total absorptance of the complete fenestration system. 7 refs., 4 figs., 1 tab.

In recent years, more and more attention has been paid on the application potential of solar cooling for buildings. Due to the fact that the efficiency of solar collectors is generally low at the time being, the effectiveness of solar cooling would be closely related to the availability of solar irradiation, climatic conditions and geographical location of a place. In this paper, five types of solar cooling systems were involved in a comparative study for subtropical city, which is commonly featured with long hot and humid summer. The solar cooling systems included the solar electric compression refrigeration, solar mechanical compression refrigeration, solar absorption refrigeration, solar adsorption refrigeration and solar solid desiccant cooling. Component-based simulation models of these systems were developed, and their performances were evaluated throughout a year. The key performance indicators are solar fraction, coefficient of performance, solar thermal gain, and primary energy consumption. In addition, different installation strategies and types of solar collectors were compared for each kind of solar cooling system. Through this comparative study, it was found that solar electric compression refrigeration and solar absorption refrigeration had the highest energy saving potential in the subtropical Hong Kong. The former is to make use of the solar electric gain, while the latter is to adopt the solar thermal gain. These two solar cooling systems would have even better performances through the continual advancement of the solar collectors. It will provide a promising application potential of solar cooling for buildings in the subtropical region. (author)

The solar energy heating system installed at the Coca-Cola Bottling Works in Jackson, Tennessee is described. The system consists of 9480 square feet of Owens-Illinois evacuated tubular solar collectors with attached specular cylindrical reflectors and will provide space heating for the 70,000 square foot production building in the winter, and hot water for the bottle washing equipment the remainder of the year. Component specifications and engineering drawings are included. (WHK)

Volume 6 Building America Best Practices Series | Department of Energy Home Technologies: Solar Thermal & Photovoltaic Systems; Volume 6 Building America Best Practices Series High-Performance Home Technologies: Solar Thermal & Photovoltaic Systems; Volume 6 Building America Best Practices Series The sixth volume of the Building America Best Practices Series presents information that is useful throughout the United States for enhancing the energy efficiency practices in the specific

Turbine Recycling and Repowering, and More | Department of Energy Solar Thermochemical Reaction Systems, Wind Turbine Recycling and Repowering, and More DOE Announces Webinars on Solar Thermochemical Reaction Systems, Wind Turbine Recycling and Repowering, and More January 8, 2015 - 8:41am Addthis EERE offers webinars to the public on a range of subjects, from adopting the latest energy efficiency and renewable energy technologies, to training for the clean energy workforce. Webinars are

Space Dust Analysis Could Provide Clues to SolarSystem Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solarsystem. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

Space Dust Analysis Could Provide Clues to SolarSystem Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solarsystem. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

Space Dust Analysis Could Provide Clues to SolarSystem Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solarsystem. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

Space Dust Analysis Could Provide Clues to SolarSystem Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solarsystem. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

Space Dust Analysis Could Provide Clues to SolarSystem Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solarsystem. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

Space Dust Analysis Could Provide Clues to SolarSystem Origins Print New studies of space dust captured by NASA's Stardust Interstellar Dust Collector have shown that interstellar particles may be much more complex in structure and composition than previously thought. -The tiny particles could give scientists chemical clues about the origins of our solarsystem. Amateur Enthusiasts Key to Research Progress The space dust that was captured by NASA's Stardust Interstellar Dust Collector landed in

Department of Energy are Homeowners and Businesses Paying for Solar Energy Systems? How are Homeowners and Businesses Paying for Solar Energy Systems? May 2, 2011 - 5:23pm Addthis David Feldman David Feldman Energy Analyst, Department of Energy's National Renewable Energy Laboratory Editor's Note: This entry has been cross-posted from DOE's Energy Blog. We commonly think that the sun provides free energy. That's true, but photovoltaic panels and other equipment to harvest that energy aren't

The Solar Deployment System (SolarDS) model is a bottom-up, market penetration model that simulates the potential adoption of photovoltaics (PV) on residential and commercial rooftops in the continental United States through 2030. NREL developed SolarDS to examine the market competitiveness of PV based on regional solar resources, capital costs, electricity prices, utility rate structures, and federal and local incentives. The model uses the projected financial performance of PV systems to simulate PV adoption for building types and regions then aggregates adoption to state and national levels. The main components of SolarDS include a PV performance simulator, a PV annual revenue calculator, a PV financial performance calculator, a PV market share calculator, and a regional aggregator. The model simulates a variety of installed PV capacity for a range of user-specified input parameters. PV market penetration levels from 15 to 193 GW by 2030 were simulated in preliminary model runs. SolarDS results are primarily driven by three model assumptions: (1) future PV cost reductions, (2) the maximum PV market share assumed for systems with given financial performance, and (3) PV financing parameters and policy-driven assumptions, such as the possible future cost of carbon emissions.

Currently, over 90% of the world's large-scale solar electric energy is generated with concentrating solar thermal power plants. Such plants have the potential to meet many of the world's future energy needs. Research efforts are generally focused on generating electricity, though a variety of other applications are being pursued. Today, the technology for using solar thermal energy is well developed, cost competitive, and in many cases, ready for widespread application. The current state of each of the solar thermal technologies and their applications is reviewed, and recommendations for increasing their use are presented. The technologies reviewed in detail are: parabolic trough systems, central tower systems, and parabolic dish systems. 20 refs., 1 fig., 1 tab.

A mirror module system is provided for accurately focusing solar radiation on a point or a line as defined by an array of solar collectors. Each mirror module includes a flexible membrane stretched over a frame in a manner similar to that of a drum or a trampoline and further includes a silvered glass or plastic mirror for forming an optical reflecting surface. The configuration of the optical reflecting surface is variably adjustable to provide for the accurate focusing of the solar energy on a given collector array, e.g., a point or a linear array arrangement. The flexible mirror-membrane combination is lightweight to facilitate installation and reduce system cost yet structurally strong enough to provide for the precise focusing of the incident solar radiation in a semi-rigid reflector system in which unwanted reflector displacement is minimized.

A mirror module system is provided for accurately focusing solar radiation on a point or a line as defined by an array of solar collectors. Each mirror module includes a flexible membrane stretched over a frame in a manner similar to that of a drum or a trampoline and further includes a silvered glass or plastic mirror for forming an optical reflecting surface. The configuration of the optical reflecting surface is variably adjustable to provide for the accurate focusing of the solar energy on a given collector array, e.g., a point or a linear array arrangement. The flexible mirror-membrane combination is lightweight to facilitate installation and reduce system cost yet structurally strong enough to provide for the precise focusing of the incident solar radiation in a semi-rigid reflector system in which unwanted reflector displacement is minimized.

(Brochure), Solar Energy Technologies Program (SETP) | Department of Energy Homeowners Guide to Financing a Grid-Connected Solar Electric System (Brochure), Solar Energy Technologies Program (SETP) Homeowners Guide to Financing a Grid-Connected Solar Electric System (Brochure), Solar Energy Technologies Program (SETP) This guide provides an overview of the financing options that may be available to homeowners who are considering installing a solar electric system on their house. 48969.pdf

Biogas has been recognized as one of the best available renewable and decentralized sources of energy and organic fertilizer for a country like India. There is enough evidence to prove that temperature has a profound influence on the rate of biogas production. In temperate climates, where the winters are mild, solar energy systems can be effectively used to increase the temperature of the biogas digester to the desired level. This paper examines various techniques, such as a solar greenhouse on the biogas digester, a shallow solar pond water heater, insulation, and a heat exchanger, and their technoeconomic viability.

The purpose of this directory is to provide a basis for market development activities through a location listing of key trade associations, trade periodicals, and key firms for three target groups. Potential industrial users and potential IPH system designers were identified as the prime targets for market development activities. The bulk of the directory is a listing of these two groups. The third group, solar IPH equipment manufacturers, was included to provide an information source for potential industrial users and potential IPH system designers. Trade associates and their publications are listed for selected four-digit Standard Industrial Code (SIC) industries. Since industries requiring relatively lower temperature process heat probably will comprise most of the near-term market for solar IPH systems, the 80 SIC's included in this chapter have process temperature requirements less than 350/sup 0/F. Some key statistics and a location list of the largest plants (according to number of employees) in each state are included for 15 of the 80 SIC's. Architectural/engineering and consulting firms are listed which are known to have solar experience. Professional associated and periodicals to which information on solar IPH sytstems may be directed also are included. Solar equipment manufacturers and their associations are listed. The listing is based on the SERI Solar Energy Information Data Base (SEIDB).

System Design Basics Solar Photovoltaic System Design Basics August 20, 2013 - 4:00pm Addthis Solar photovoltaic modules are where the electricity gets generated, but are only one of the many parts in a complete photovoltaic (PV) system. In order for the generated electricity to be useful in a home or business, a number of other technologies must be in place. Mounting Structures PV arrays must be mounted on a stable, durable structure that can support the array and withstand wind, rain, hail,

The Energy Department will present a live webinar titled "Potential Strategies for Integrating Solar Hydrogen Production and Concentrating Solar Power: A Systems Analysis" on Thursday, November 19, from 1:00 to 2:00 p.m. EST. This webinar will present the results of an analysis conducted by Sandia National Laboratories that explored potential synergies that may be realized by integrating solar hydrogen production and concentrating solar power (CSP) technologies.

The Energy Department will present a live webinar titled "Potential Strategies for Integrating Solar Hydrogen Production and Concentrating Solar Power: A Systems Analysis" on Thursday, January 21, from 12 to 1 p.m. EST. This webinar will present the results of an analysis conducted by Sandia National Laboratories that explored potential synergies that may be realized by integrating solar hydrogen production and concentrating solar power (CSP) technologies.

Several applications of solar energy have proven viable in the energy marketplace, due to competitive technology and economic performance. One example is the parabolic trough solar collectors, which use focused solar energy to maximize efficiency and reduce material use in construction. Technical improvements are complemented by new business practices to make parabolic trough solar thermal systems technically and economically viable in an ever widening range of applications. Technical developments in materials and fabrication techniques reduce production cost and expand applications from swimming pool heating and service hot water, to higher-temperature applications such as absorption cooling and process steam. Simultaneously, new financing mechanisms such as a recently awarded US Department of Energy (DOE) Federal Energy Management Program (FEMP) indefinite quantity Energy Savings Performance Contract (Super ESPC) facilitate and streamline implementation of the technology in federal facilities such as prisons and military bases.

The Solar Thermal Power Systems Program is the key element in the national effort to establish solar thermal conversion technologies within the major sectors of the national energy market. It provides for the development of concentrating mirror/lens heat collection and conversion technologies for both central and dispersed receiver applications to produce electricity, provide heat at its point of use in industrial processes, provide heat and electricity in combination for industrial, commercial, and residential needs, and ultimately, drive processes for production of liquid and gaseous fuels. This report is the second Annual Technical Progress Report for the Solar Thermal Power Systems Program and is structured according to the organization of the Solar Thermal Power Systems Program on September 30, 1979. Emphasis is on the technical progress of the projects rather than on activities and individual contractor efforts. Each project description indicates its place in the Solar Thermal Power Systems Program, a brief history, the significant achievements and real progress during FY 1979, also future project activities as well as anticipated significant achievements are forecast. (WHK)

The heat pump system with a refrigerant-filled evaporator consists of a standard air-to-air or air-to-liquid heat pump that utilizes a solar panel as the evaporator. A combination of solar energy and convection heat transfer acts as the ''free'' energy absorbed by the collector/evaporator. In this paper, the seasonal performance of such systems for industrial applications will be presented. Performance of collector/evaporator heat pumps will be compared with alternative heat pump and solarsystems. The benefits of covered and coverless collector/evaporators will be discussed. Results to date have shown that refrigerant-filled collector heat pumps do not perform as well as conventional heat pumps at small collector areas but have as much as 15% performance improvement over conventional heat pumps at an appropriate collector area.

An experimental solar-assisted heat pump system with solar energy storage in encapsulated phase change material (PCM) packings at the Karadeniz Technical University in Trabzon, Turkey is described. It includes 30 m{sup 2} solar collectors, a latent-heat thermal energy storage tank filled with PCM, a heat exchanger, a heat pump with double evaporators and condenser, and a conventional air conditioning channel. The authors have analyzed the system's behavior from July to August, 1990. The data processed has shown that each of the systems has apparently performed adequately. Collector efficiency is 0.80, heat pump coefficient of performance range is around 7, and the storage efficiency reaches 0.60. When the investigations are accomplished, they will publish the experimental results in detail.

This article describes the development of a solar water heating system appropriate for low-income Florida residents and the appliances developed in conjunction with it that may appeal to a wider market. Among the topics discussed are size and design of the system including passive preheaters and affordable active systems. Electric water heaters with 40 and 50 gallon capacity were found to be the most cost effective. The feed-back from customers is also discussed. 3 figs.

This thesis is a design of an alternative system which may provide heating to the Naval Postgraduate School swimming pool. Particularly, it is a solar heating/photovoltaic system designed for a better efficiency and less cost of installation and maintenance. Principles of heat transfer, control and fluid dynamics theory are used for the determination of this heating system elements. The feasibility of its installation and use is analyzed.

To secure competitive financing for a solar energy generation project, the economic risk associated with interannual solar resource variability must be quantified. One way to quantify this risk is to calculate exceedance probabilities representing the amount of energy expected to be produced by a plant. Many years of solar radiation and metereological data are required to determine these values, often called P50 or P90 values for the level of certainty they represent. This paper describes the two methods implemented in the National Renewable Energy Laboratory's System Advisor Model (SAM) to calculate P50 and P90 exceedance probabilities for solar energy projects. The methodology and supporting data sets are applicable to photovoltaic, solar water heating, and concentrating solar power (CSP) systems.

Within the Solar Thermal Research and Advanced Development (RAD) program a coordinated effort in materials research, fuels and chemical research and applied research is being carried out to meet the systems' needs. Each of these three program elements are described with particular attention given to the applied research activity.

A solar process heat (SPH) data network has been developed to access remote-site performance data from operational solar heat systems. Each SPH system in the data network is outfitted with monitoring equipment and a datalogger. The datalogger is accessed via modem from the data network computer at the National Renewable Energy Laboratory (NREL). The dataloggers collect both ten-minute and hourly data and download it to the data network every 24-hours for archiving, processing, and plotting. The system data collected includes energy delivered (fluid temperatures and flow rates) and site meteorological conditions, such as solar insolation and ambient temperature. The SPH performance data network was created for collecting performance data from SPH systems that are serving in industrial applications or from systems using technologies that show promise for industrial applications. The network will be used to identify areas of SPH technology needing further development, to correlate computer models with actual performance, and to improve the credibility of SPH technology. The SPH data network also provides a centralized bank of user-friendly performance data that will give prospective SPH users an indication of how actual systems perform. There are currently three systems being monitored and archived under the SPH data network: two are parabolic trough systems and the third is a flat-plate system. The two trough systems both heat water for prisons; the hot water is used for personal hygiene, kitchen operations, and laundry. The flat plate system heats water for meat processing at a slaughter house. We plan to connect another parabolic trough system to the network during the first months of 1996. We continue to look for good examples of systems using other types of collector technologies and systems serving new applications (such as absorption chilling) to include in the SPH performance data network.

The characteristics, design and environmental requirements, and economic data are defined for a Solar Central Receiver System Integrated with a Cogeneration Facility for Copper Smelting. The added solar capacity will supply process heat to an existing copper smelting flash furnace of Finnish design as well as providing for the cogeneration of electricity by an added gas turbine system. Heat storage to accommodate periods of low solar insolation is accomplished by the innovative utilization of copper slag in a thermal energy storage system. The proposed modifications and existing site conditions and facilities are described. Applicable standards and codes, publications, reference documentation, and regulatory information are listed. Design and performance requirements to be met by this solar cogeneration facility are outlined, and the environmental criteria applicable to the plant are addressed. The solar cogeneration facility's characteristics and performance data are specified, along with the plant cost and economic data. Simulation models are also described.

We have applied an optical splitting system in order to achieve very high conversion efficiency for a full spectrum multi-junction solar cell. This system consists of multiple solar cells with different band gap optically coupled via an âoptical splitter.â An optical splitter is a multi-layered beam splitter with very high reflection in the shorter-wave-length range and very high transmission in the longer-wave-length range. By splitting the incident solar spectrum and distributing it to each solar cell, the solar energy can be managed more efficiently. We have fabricated optical splitters and used them with a wide-gap amorphous silicon (a-Si) solar cell or a CH{sub 3}NH{sub 3}PbI{sub 3} perovskite solar cell as top cells, combined with mono-crystalline silicon heterojunction (HJ) solar cells as bottom cells. We have achieved with a 550ânm cutoff splitter an active area conversion efficiency of over 25% using a-Si and HJ solar cells and 28% using perovskite and HJ solar cells.

For tropical countries, solar space cooling is an attractive proposition. Dehumidification of air in hot, humid climates is almost as important as cooling. Removal of moisture from the air is much easier to achieve than cooling the air. The proposed cooling system operates on the ventilation mode. The ambient air is dehumidified using liquid desiccants followed by adiabatic evaporative cooling. The desiccant soon becomes saturated with the water extracted from the air and can be regenerated by using solar energy. For this system, a simple expression is derived in this paper to predict the amount of heat removed from the space to be conditioned in terms of known initial parameters through a simplified vapor pressure correlation and effectiveness of the dehumidifier and the heat exchanger. The effect of ambient air conditions, solution concentration, the cooling water temperature and the effectiveness of the dehumidifier and the heat exchanger on the performance of the cooling system are also discussed in this paper.

The turbocompressor comprises a power turbine and a compressor turbine having respective rotors and on a common shaft, rotatably supported by bearings. A first working fluid is supplied by a power loop and is expanded in the turbine. A second working fluid is compressed in the turbine and is circulated in a heat pump loop. A lubricant is mixed with the second working fluid but is excluded from the first working fluid. The bearings are cooled and lubricated by a system which circulates the second working fluid and the intermixed lubricant through the bearings. Such system includes a pump, a thermostatic expansion valve for expanding the working fluid into the space between the bearings, and a return conduit system for withdrawing the expanded working fluid after it passes through the bearings and for returning the working fluid to the evaporator. A shaft seal excludes the lubricant from the power turbine. The power loop includes a float operable by liquid working fluid in the condenser for controlling a recirculation valve so as to maintain a minimum liquid level in the condenser, while causing a feed pump to pump most of the working fluid into the vapor generator. The heat pump compressor loop includes a float in the condenser for operating and expansion valve to maintain a minimum liquid working fluid level in the condenser while causing most of the working fluid to be expanded into the evaporator.

EERE's Solar Energy Technologies Program is charged with leading the Secretary's SunShot Initiative to reduce the cost of electricity from solar by 75% to be cost competitive with conventional energy sources without subsidy by the end of the decade. As part of this Initiative, the program has funded the National Renewable Energy Laboratory (NREL) to develop module manufacturing and solar PV system installation cost models to ensure that the program's cost reduction targets are carefully aligned with current and near term industry costs. The NREL cost analysis team has leveraged the laboratories' extensive experience in the areas of project finance and deployment, as well as industry partnerships, to develop cost models that mirror the project cost analysis tools used by project managers at leading U.S. installers. The cost models are constructed through a "bottoms-up" assessment of each major cost element, beginning with the system's bill of materials, labor requirements (type and hours) by component, site-specific charges, and soft costs. In addition to the relevant engineering, procurement, and construction costs, the models also consider all relevant costs to an installer, including labor burdens and overhead rates, supply chain costs, and overhead and materials inventory costs, and assume market-specific profits.

Initiated in 2008, the Solar Energy Grid Integration Systems (SEGIS) program is a partnership involving the U.S. DOE, Sandia National Laboratories, private sector companies, electric utilities, and universities. Projects supported under the program have focused on the complete-system development of solar technologies, with the dual goal of expanding utility-scale penetration and addressing new challenges of connecting large-scale solar installations in higher penetrations to the electric grid. The Florida Solar Energy Center (FSEC), its partners, and Sandia National Laboratories have successfully collaborated to complete the work under the third and final stage of the SEGIS initiative. The SEGIS program was a three-year, three-stage project that include conceptual design and market analysis in Stage 1, prototype development and testing in Stage 2, and moving toward commercialization in Stage 3. Under this program, the FSEC SEGIS team developed a comprehensive vision that has guided technology development that sets one methodology for merging photovoltaic (PV) and smart-grid technologies. The FSEC team's objective in the SEGIS project is to remove barriers to large-scale general integration of PV and to enhance the value proposition of photovoltaic energy by enabling PV to act as much as possible as if it were at the very least equivalent to a conventional utility power plant. It was immediately apparent that the advanced power electronics of these advanced inverters will go far beyond conventional power plants, making high penetrations of PV not just acceptable, but desirable. This report summarizes a three-year effort to develop, validate and commercialize Grid-Smart Inverters for wider photovoltaic utilization, particularly in the utility sector.

This webinar has been postponed until further notice. The Energy Department will present a live webinar titled "Potential Strategies for Integrating Solar Hydrogen Production and Concentrating Solar Power: A Systems Analysis" on Thursday, November 19, from 1:00 to 2:00 p.m. EST.

The purpose of the survey was to understand the motivation, challenges and benefits perceived by individuals who decided to install solarsystems in the City of San Diego. Approximately 2000 surveys were sent, and 641 surveys were completed. The primary response was from the residential sector. Individuals had the option to reply electronically, using Survey Monkey, or to complete a paper survey. All responses were combined and checked to ensure that there were no duplicates.

Forest County Potawatomi Community Installation of Solar Photovoltaic Systems Presented by: Nathan Karman Legal Department Forest County Potawatomi Community March 27, 2014 "Let us share our natural resources for the good of our People. Let us work for clean air and water and pray for the courage to stand up to those who would abuse our Mother Earth. So be it." - Bemwetek (Elder James Thunder) Excerpt from 2007 Class I Air Redesignation Public Hearing Prayer Community's Commitment to

Technical briefing to report the outcomes of a data monitoring effort to determine the nature of solar vent preheat system performance problems at a U.S. military installation. The analysis reports up-to-date research and findings regarding system design, helping to clarify the issue as a factor of system design, rather than a shortcoming of SVP systems.

We report the discovery and orbital determination of 14 trans-Neptunian objects (TNOs) from the ESSENCE Supernova Survey difference imaging data set. Two additional objects discovered in a similar search of the SDSS-II Supernova Survey database were recovered in this effort. ESSENCE repeatedly observed fields far from the solarsystem ecliptic (-21{sup o} < {beta} < -5{sup o}), reaching limiting magnitudes per observation of I {approx} 23.1 and R {approx} 23.7. We examine several of the newly detected objects in detail, including 2003 UC{sub 414}, which orbits entirely between Uranus and Neptune and lies very close to a dynamical region that would make it stable for the lifetime of the solarsystem. 2003 SS{sub 422} and 2007 TA{sub 418} have high eccentricities and large perihelia, making them candidate members of an outer class of TNOs. We also report a new member of the 'extended' or 'detached' scattered disk, 2004 VN{sub 112}, and verify the stability of its orbit using numerical simulations. This object would have been visible to ESSENCE for only {approx}2% of its orbit, suggesting a vast number of similar objects across the sky. We emphasize that off-ecliptic surveys are optimal for uncovering the diversity of such objects, which in turn will constrain the history of gravitational influences that shaped our early solarsystem.

In late 2007, the U.S. Department of Energy (DOE) initiated a series of studies to address issues related to potential high penetration of distributed photovoltaic (PV) generation systems on our nationâs electric grid. This Renewable Systems Interconnection (RSI) initiative resulted in the publication of 14 reports and an Executive Summary that defined needs in areas related to utility planning tools and business models, new grid architectures and PV systems configurations, and models to assess market penetration and the effects of high-penetration PV systems. As a result of this effort, the Solar Energy Grid Integration Systems (SEGIS) program was initiated in early 2008. SEGIS is an industry-led effort to develop new PV inverters, controllers, and energy management systems that will greatly enhance the utility of distributed PV systems.

This document is intended to serve as a specification for generic solar photovoltaic (PV) system positive-sequence dynamic models to be implemented by software developers and approved by the WECC MVWG for use in bulk system dynamic simulations in accordance with NERC MOD standards. Two specific dynamic models are included in the scope of this document. The first, a Central Station PV System model, is intended to capture the most important dynamic characteristics of large scale (> 10 MW) PV systems with a central Point of Interconnection (POI) at the transmission level. The second, a Distributed PV System model, is intended to represent an aggregation of smaller, distribution-connected systems that comprise a portion of a composite load that might be modeled at a transmission load bus.

The paper reports progress on three tasks. Task A, System comparison of hydrogen with other alternative fuels in terms of EPACT requirements, investigates the feasibility of several alternative fuels, namely, natural gas, methanol, ethanol, hydrogen and electricity, to replace 10% of gasoline by the year 2000. The analysis was divided into two parts: analysis of vehicle technologies and analysis of fuel production, storage and distribution. Task B, Photovoltaic hydrogen production, involves this fuel production method for the future. The process uses hybrid solar collectors to generate dc electricity, as well as high temperature steam for input to the electrolyzer. During the first year, solar to hydrogen conversion efficiencies have been considered. The third task, Hydrogen safety studies, covers two topics: a review of codes, standards, regulations, recommendations, certifications, and pamphlets which address safety of gaseous fuels; and an experimental investigation of hydrogen flame impingement.

The invention provides an improved optical system for determining the physical characteristics of a solar cell. The system comprises a lamp means for projecting light in a wide solid-angle onto the surface of the cell; a chamber for receiving the light through an entrance port, the chamber having an interior light absorbing spherical surface, an exit port for receiving a beam of light reflected substantially normal to the cell, a cell support, and an lower aperture for releasing light into a light absorbing baffle; a means for dispersing the reflection into monochromatic components; a means for detecting an intensity of the components; and a means for reporting the determination.

The benefits of leases for solar electric equipment include lower upfront costs and no operation and maintenance responsibilities. t e c h n i c a l a s s i s ta n c e Homeowners Guide to Leasing a Solar Electric System This guide provides an introduction to solar leases for homeowners considering installing a solar electric system on their home. Introduction Solar electric systems, also known as photovoltaic (PV) systems, allow owners to generate a portion of their own electricity. Homeowners

| NREL SolarCity and the Hawaiian Electric Companies NREL is collaborating with SolarCity at the Energy Systems Integration Facility (ESIF) to address the safety, reliability, and stability challenges of interconnecting high penetrations of distributed photovoltaics (PV) with the electric power system. "We know how important the option of solar is for our customers. Solving these issues requires that everyone-utilities, the solar industry, and other leading technical experts like

SunShot Initiative Installs Solar Energy System SunShot Initiative Installs Solar Energy System Addthis 1 of 10 SunShot Initiative team members install a solar energy system on a Habitat for Humanity home in Washington, D.C. on Friday, September 19. The project was organized by GRID Alternatives, the nation's largest solar non-profit organization, as part of a two-day event to bring solar power to underserved communities. Image: Jamie Nolan 2 of 10 A volunteer from the SunShot Initiative helps

Department of Energy SunShot Installs Solar Energy System on Local Habitat for Humanity Home SunShot Installs Solar Energy System on Local Habitat for Humanity Home September 22, 2014 - 5:10pm Addthis 1 of 10 SunShot Initiative team members install a solar energy system on a Habitat for Humanity home in Washington, D.C. on Friday, September 19. The project was organized by GRID Alternatives, the nation's largest solar non-profit organization, as part of a two-day event to bring solar power

Solar Decathlon 2015 Solar Decathlon 2015 Addthis 1 of 69 Stevens Institute of Technology won top honors at the U.S. Department of Energy Solar Decathlon on October 17, 2015 overall by designing, building, and operating the most cost-effective, energy-efficient and attractive solar powered house. University at Buffalo, The State University of New York took second place followed by California Polytechnic State University, San Luis Obispo in third place. Image: Thomas Kelsey, U.S. Department of

Federal buildings consumed over 392,000 billion Btu of site delivered energy for buildings during FY 2007 at a total cost of $6.5 billion. Earlier data indicate that about 10% of this is used to heat water.[2] Targeting energy consumption in Federal buildings, the Energy Independence and Security Act of 2007 (EISA) requires new Federal buildings and major renovations to meet 30% of their hot water demand with solar energy, provided it is cost-effective over the life of the system. In October 2009, President Obama expanded the energy reduction and performance requirements of EISA and its subsequent regulations with his Executive Order 13514.

It has been shown that generalized Einstein-Aether theories may lead to significant modifications to the nonrelativistic limit of the Einstein equations. In this paper we study the effect of a general class of such theories on the SolarSystem. We consider corrections to the gravitational potential in negative and positive powers of distance from the source. Using measurements of the perihelion shift of Mercury and time delay of radar signals to Cassini, we place constraints on these corrections. We find that a subclass of generalized Einstein-Aether theories is compatible with these constraints.

A solar thermal energy collection and storage system is disclosed. Water is contained, and the water surface is exposed directly to the sun. The central part of an impermeable membrane is positioned below the water's surface and above its bottom with a first side of the membrane pointing generally upward in its central portion. The perimeter part of the membrane is placed to create a watertight boundary separating the water into a first volume which is directly exposable to the sun and which touches the membranes first side, and a second volumn which touches the membranes second side. A salt is dissolved in the first water volume.

This manual was prepared as a text for a training course on solar heating and cooling of residential buildings. The course and text are directed toward sizing, installation, operation, and maintenance of solarsystems for space heating and hot water supply, and solar cooling is treated only briefly. (MHR)

The characteristics and design and environmental requirements are specified for a solar cogeneration facility at the Fort Hood Army Base in Killeen, Texas. Characteristics of the system and major elements are described, and applicable standards, codes, laws and regulations are listed. Performance requirements for the total system and for each individual subsystem are presented. Survival requirements are given for various environmental extremes, with consideration given to lightning protection and effects of direct or adjacent lightning strikes. Air quality control standards are briefly mentioned. The facility operates in two principal modes: energy collection and energy utilization. The plant is capable of operating in either mode independently or in both modes simultaneously. The system is also operational in transitional and standby/inactive modes. (LEW)

A low-temperature solar Rankine system utilizing R245fa as the working fluid is proposed and an experimental system is designed, constructed and tested. Both the evacuated solar collectors and the flat plate solar collectors are used in the experimental system; meanwhile, a rolling-piston R245fa expander is also mounted in the system. The new designed R245fa expander works stably in the experiment, with an average expansion power output of 1.73 kW and an average isentropic efficiency of 45.2%. The overall power generation efficiency estimated is 4.2%, when the evacuated solar collector is utilized in the system, and with the condition of flat plate solar collector, it is about 3.2%. The experimental results show that using R245fa as working fluid in the low-temperature solar power Rankine cycle system is feasible and the performance is acceptable. (author)

This paper is concerned with theories of gravity that contain a scalar coupled both conformally and disformally to matter through the metric. By systematically deriving the non-relativistic limit, it is shown that no new non-linear screening mechanisms are present beyond the Vainshtein mechanism and chameleon-like screening. If one includes the cosmological expansion of the universe, disformal effects that are usually taken to be absent can be present in the solarsystem. When the conformal factor is absent, fifth-forces can be screened on all scales when the cosmological field is slowly-rolling. We investigate the cosmology of these models and use local tests of gravity to place new constraints on the disformal coupling and find M ?> O(eV), which is not competitive with laboratory tests. Finally, we discuss the future prospects for testing these theories and the implications for other theories of modified gravity. In particular, the Vainshtein radius of solarsystem objects can be altered from the static prediction when cosmological time-derivatives are non-negligible.

The deployment of solar photovoltaic (PV) systems has grown rapidly over the last decade, partly because of various government incentives. In the United States, those established in California are among the largest and longest-running incentives. Building on past research, this report addresses the still-unanswered question: to what degree have the direct PV incentives in California been passed along from installers to consumers? This report addresses this question by carefully examining the residential PV market in California and applying both a structural-modeling approach and a reduced-form regression analysis to estimate the incentive pass-through rate. The results suggest an average pass-through rate of direct incentives of nearly 100%, but with regional differences among California counties. While these results could have multiple explanations, they suggest a relatively competitive market and well-functioning subsidy program. Further analysis is required to determine whether similar results broadly apply to other states, to other customer segments, to all third-party-owned PV systems, or to all forms of financial incentives for solar.

of Energy Soft Costs Â» Solar Projects to Reduce Non-Hardware Balance of System Costs Solar Projects to Reduce Non-Hardware Balance of System Costs -- These projects are inactive -- Seven projects are focused on creating tools and developing methods to reduce the cost of non-hardware components for installed solar energy systems and reducing market barriers. These projects will develop software design tools and databases that can be used by local jurisdictions and installers, and tools to

The diurnal nature of solar power is made uncertain by variable cloud cover and the influence of atmospheric conditions on irradiance scattering processes. Its forecasting has become increasingly important to the unit commitment and dispatch process for efficient scheduling of generators in power system operations. This study examines the value of improved solar power forecasting for the Independent System Operator-New England system. The results show how 25% solar power penetration reduces net electricity generation costs by 22.9%.

This paper presents, from a financing aspect the broad issues involved in a plan to provide solar home systems (SHS) to provide rural electrification in several areas of rural Indonesia. The paper discusses the approaches being used to provide funding, develop awareness of the technology, and assure the success of the project. The plan involves the use of grant money to help with some of the initial costs of such systems, and thereby to encourage local financing on a terms rather than cash basis. There are needs for market development, and development of a business structure in the country to support this type of technology. Provided this plan can succeed, it may serve as a model for further efforts.

Newly developed solar water heating technology can help Federal agencies cost effectively meet the EISA requirements for solar water heating in new construction and major renovations. This document provides design considerations, application, economics, and maintenance information and resources.

Literature summarizing a study on the Saudi Arabian solar controlled environment agriculture system is presented. Specifications and performance requirements for the system components are revealed. Detailed performance and cost analyses are used to determine the optimum design. A preliminary design of an engineering field test is included. Some weather data are provided for Riyadh, Saudi Arabia. (BCS)

A combustion system for a hybrid solar receiver comprises a pre-mixer which combines air and fuel to form an air-fuel mixture. The mixture is introduced tangentially into a cooling jacket. A burner plenum is fluidically connected to the cooling jacket such that the burner plenum and the cooling jacket are arranged in thermal contact with one another. The air-fuel mixture flows through the cooling jacket cooling the burner plenum to reduce pre-ignition of the air-fuel mixture in the burner plenum. A combustion chamber is operatively associated with and open to the burner plenum to receive the air-fuel mixture from the burner plenum. An igniter is operatively positioned in the combustion chamber to combust the air-fuel mixture, releasing heat. A recuperator is operatively associated with the burner plenum and the combustion chamber and pre-heats the air-fuel mixture in the burner plenum with heat from the combustion chamber. A heat-exchanger is operatively associated and in thermal contact with the combustion chamber. The heat-exchanger provides heat for the hybrid solar receiver.

As a background for solar applications, the following topics are covered: solarsystems and components for retrofit installations; cost, performance, and quality considerations; and financing alternatives for local government. The retrofit decision process is discussed as follows: pre-screening of buildings, building data requirements, the energy conservation audit, solarsystem sizing and economics, comparison of alternatives, and implementation. Sample studies are presented for the West Valley Animal Shelter and the Hollywood Police Station. (MHR)

The paper reviews the performance characteristics of various passive solar heating systems for buildings, the main design factors affecting their performance, the relative advantages and main problems associated with them, and their applicability to different building types and climatic regions. Emphasis is placed on the architectural design issues associated with the different passive solar heating systems and to the problems that may be encountered when passive solar heating is applied in regions with hot summers.

The U.S. Department of Energy's National Renewable Energy Laboratory collaborates with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result is high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.

The U.S. Department of Energy's National Renewable Energy Laboratory collaborates with the solar industry to establish high quality solar and meteorological measurements. This Solar Resource and Meteorological Assessment Project (SOLRMAP) provides high quality measurements to support deployment of power projects in the United States. The no-funds-exchanged collaboration brings NREL solar resource assessment expertise together with industry needs for measurements. The end result is high quality data sets to support the financing, design, and monitoring of large scale solar power projects for industry in addition to research-quality data for NREL model development. NREL provides consultation for instrumentation and station deployment, along with instrument calibrations, data acquisition, quality assessment, data distribution, and summary reports. Industry participants provide equipment, infrastructure, and station maintenance.

Performance data was collected and analyzed for a solar heating system installed on the Field House at Louisiana State University. The solarsystem performed as expected for periods that it operated. Problems encountered are discussed. Efficiency of flat-plate collectors used was determined. 2 refs.

This book presents a systematic and standardized approach to the preparation of operation and maintenance manuals for active solar heating systems. Provides an industry consensus of the best operating and maintenance procedures for large commercial-scale solar service water and space heating systems. A sample O M manual is included. 3-ring binder included.

A simple innovative solar heating design (Solar Option One) using conventional hydronic solar collectors and a radiant panel slab was constructed. An objective of hybrid solar design is to combine the relative advantages of active and passive design approaches while minimizing their respective disadvantages. A test house using the Solar Option One heating system was experimentally monitored to determine its energy based performance during the 1982-83 heating season. The test residence is located in Lyndonville, Vermont, an area which has a characteristically cold and cloudy climate. The two story residence has a floor area of about 1400 square feet and is constructed on a 720 square foot 5.5 inch thick floor slab. A 24 inch packed gravel bed is located beneath the slab and the slab-gravel bed is insulated by two inches of polystyrene insulation. The test building is of frame construction and uses insulation levels which have become commonplace throughout the country. The structure would not fall into the superinsulated category but was tightly constructed so as to have a low infiltration level. The building is sun-tempered in that windows were concentrated somewhat on the South side and all but avoided on the North. A solar greenhouse on the South side of the building was closed off from the structure permanently throughout the testing so as to better observe the solar heating invention without confounding variables. The monitoring equipment generated an internal gain of about 17,000 BTUs per day, roughly the equivalent of occupancy by two persons. A full description of the experimental testing program is given. System efficiency and performance are reported.

The performance of a solar multieffect desalination pilot plant has been studied over an extended period of one year. The impact of solar flux, ambient and sea water temperatures on the monthly average water production and plant performance ratios are investigated. The specific thermal and electric energy requirements of the system have been examined and compared with the requirements of conventional fossil fuel powered desalination plants. The economic viability of the solar desalination system has been assessed. It reveals that the capital and operating costs represent around 93 and 7 percent of the overall water production cost respectively. The capital cost critically depends on solar radiation and distiller performance ratio.

The Department of Housing and Urban Development (HUD) residential solar heating and cooling demonstration program provided funding support for over 600 solar projects. These projects provide the largest single data base of solar heating and cooling experience now available. These data suggest that maintenance and system operation have been mixed even though system configurations are similar throughout the program. HUD has been involved in the upgrading of one-third of the 600 solar projects and now can report that projects can be maintained with a more uniform level of effort.

The Solar Heating System installer guidelines are provided for each subsystem and includes testing and filling the system. This single-family residential heating system is a solar-assisted, hydronic-to-warm-air system with solar-assisted domestic water heating. It is composed of the following major components: liquid cooled flat plate collectors; water storage tank; passive solar-fired domestic water preheater; electric hot water heater; heat pump with electric backup; solar hot water coil unit; tube-and-shell heat exchanger, three pumps, and associated pipes and valving in an energy transport module; control system; and air-cooled heat purge unit. Information is also provided on the operating procedures, controls, caution requirements, and routine and schedule maintenance. Information consists of written procedures, schematics, detail drawings, pictures and manufacturer's component data.

SPI Solar and Trimark SPI Solar, Trimark, and NREL are partnering to optimize the thermal and optical performance of parabolic trough receivers-critical components of concentrating solar power (CSP) plants. Photo of parabolic trough receiver equipment in a laboratory Photo by Dennis Schroeder Receivers in CSP plants take a lot of abuse, from dramatic temperature changes to numerous mechanical stresses. Finding ways to make the receivers more resilient and optimize their performance under these

Integration | NREL New Partnerships Help Utilities Break Down Solar Barriers May 11, 2016 The Solar Technical Assistance Team (STAT) Network launched its first program of technical assistance to electric utilities and announced three new efforts to provide direct support to utility partners. The activities range from providing interconnection training to conducting detailed techno-economic modeling to leveraging community solar finance tools. The National Renewable Energy Laboratory (NREL),

The following systems are discussed: energy self-sufficient farms, wood gasification, energy from high-yield silviculture farms, and solar district heating and cooling. System descriptions and environmental data are included for each one. (MHR)

The Ivanpah Solar Electric Generating System (ISEGS), located on I-15 about 40 miles (60 km) south of Las Vegas, NV, consists of three power towers 459 ft (140 m) tall and over 170,000 reflective heliostats with a rated capacity of 390 MW. In addition, reports of glare from the plant have been submitted by pilots and air traffic controllers and recorded by the Aviation Safety Reporting System and the California Energy Commission since 2013. Aerial and ground-based surveys of the glare were conducted in April, 2014, to identify the cause and to quantify the irradiance and potential ocular impacts of the glare. Results showed that the intense glare viewed from the airspace above ISEGS was caused by heliostats in standby mode that were aimed to the side of the receiver. Evaluation of the glare showed that the retinal irradiance and subtended source angle of the glare from the heliostats in standby were sufficient to cause significant ocular impact (potential for after-image) up to a distance of ~6 miles (10 km), but the values were below the threshold for permanent eye damage. Glare from the receivers had a low potential for after-image at all ground-based monitoring locations outside of the site boundaries. A Letter to Airmen has been issued by the Federal Aviation Administration to notify pilots of the potential glare hazards. Additional measures to mitigate the potential impacts of glare from ISGES are also presented and discussed.

The Ivanpah Solar Electric Generating System (ISEGS), located on I-15 about 40 miles (60 km) south of Las Vegas, NV, consists of three power towers 459 ft (140 m) tall and over 170,000 reflective heliostats with a rated capacity of 390 MW. In addition, reports of glare from the plant have been submitted by pilots and air traffic controllers and recorded by the Aviation Safety Reporting System and the California Energy Commission since 2013. Aerial and ground-based surveys of the glare were conducted in April, 2014, to identify the cause and to quantify the irradiance and potential ocular impacts ofmoreÂ Â» the glare. Results showed that the intense glare viewed from the airspace above ISEGS was caused by heliostats in standby mode that were aimed to the side of the receiver. Evaluation of the glare showed that the retinal irradiance and subtended source angle of the glare from the heliostats in standby were sufficient to cause significant ocular impact (potential for after-image) up to a distance of ~6 miles (10 km), but the values were below the threshold for permanent eye damage. Glare from the receivers had a low potential for after-image at all ground-based monitoring locations outside of the site boundaries. A Letter to Airmen has been issued by the Federal Aviation Administration to notify pilots of the potential glare hazards. Additional measures to mitigate the potential impacts of glare from ISGES are also presented and discussed.Â«Â less

This work describes measurements of the solar irradiance made during cloudy periods in order to improve the amount of solar energy captured during such periods. It is well-known that 2-axis tracking, in which solar modules are pointed at the sun, improves the overall capture of solar energy by a given area of modules by 30-50% versus modules with a fixed tilt. On sunny days the direct sunshine accounts for up to 90% of the total solar energy, with the other 10% from diffuse (scattered) solar energy. However, during overcast conditions nearly all of the solar irradiance is diffuse radiation that is isotropically-distributed over the whole sky. An analysis of our data shows that during overcast conditions, tilting a solar module or sensor away from the zenith reduces the irradiance relative to a horizontal configuration, in which the sensor or module is pointed toward the zenith (horizontal module tilt), and thus receives the highest amount of this isotropically-distributed sky radiation. This observation led to an improved tracking algorithm in which a solar array would track the sun during cloud-free periods using 2-axis tracking, when the solar disk is visible, but go to a horizontal configuration when the sky becomes overcast. During cloudy periods we show that a horizontal module orientation increases the solar energy capture by nearly 50% compared to 2-axis solar tracking during the same period. Improving the harvesting of solar energy on cloudy days is important to using solar energy on a daily basis for fueling fuel-cell electric vehicles or charging extended-range electric vehicles because it improves the energy capture on the days with the lowest hydrogen generation, which in turn reduces the system size and cost. (author)

This paper presents the Concentrating Solar Deployment System Model (CSDS). CSDS is a multiregional, multitime-period, Geographic Information System (GIS), and linear programming model of capacity expansion in the electric sector of the United States. CSDS is designed to address the principal market and policy issues related to the penetration of concentrating solar power (CSP) electric-sector technologies. This paper discusses the current structure, capabilities, and assumptions of the model. Additionally, results are presented for the impact of continued research and development (R&D) spending, an extension to the investment tax credit (ITC), and use of a production tax credit (PTC). CSDS is an extension of the Wind Deployment System (WinDS) model created at the National Renewable Energy Laboratory (NREL). While WinDS examines issues related to wind, CSDS is an extension to analyze similar issues for CSP applications. Specifically, a detailed representation of parabolic trough systems with thermal storage has been developed within the existing structure.

A hybrid solar/gas receiver system will allow Stirling engines to operate with combined solar and gas power sources. One of the most attractive options for building a hybrid system is to integrate a gas-fired heat pipe directly into a heat-pipe solar receiver. Before this union can take place, however, a number of technical issues must be resolved. A design must be found that properly distributes the heat-pipe's working fluid over the heated surfaces and prevents fluid from accumulating at undesirable locations in the heat pipe. Experience that has been gained in developing solar receivers and gas-fired heat pipes under recent Department of Energy solar-thermal dish-electric programs is used in this paper to address many of the technical obstacles to building receiver systems. 16 refs.

A hybrid solar/gas receiver system will allow Stirling engines to operate with combined solar and gas power sources. One of the most attractive options for building a hybrid system is to integrate a gas-fired heat pipe directly into a heat-pipe solar receiver. Before this union can take place, however, a number of technical issues must be resolved. A design must be found that properly distributes the heat-pipe`s working fluid over the heated surfaces and prevents fluid from accumulating at undesirable locations in the heat pipe. Experience that has been gained in developing solar receivers and gas-fired heat pipes under recent Department of Energy solar-thermal dish-electric programs is used in this paper to address many of the technical obstacles to building receiver systems. 16 refs.

Information is provided on the solar heating and hot water system installed at the William Tao and Associates, Inc., office building in St. Louis, Missouri. The information consists of description, photos, maintenance and construction problems, final drawing, system requirements and manufacturer's component data. The solarsystem was designed to provide 50% of the hot water requirements and 45% of the space heating needs for a 900 square foot office space and drafting room. The solar facility has 252 square foot of glass tube concentrator collectors and a 1000 gallon steel storage tank buried below a concrete slab floor. Freeze protection is provided by a propylene glycol/water mixture in the collector loop. The collectors are roof mounted on a variable tilt array which is adjusted seasonally and is connected to the solar thermal storage tank by a tube-in-shell heat exchanger. Incoming city water is preheated through the solar energy thermal storage tank.

Catalytic Inc. was awarded a contract to conduct a preliminary system design and cost analysis for a brackish water desalination project to be located in Brownsville, Texas. System analyses and economic analyses were performed to define the baseline solar energy desalination system. The baseline system provides an average daily product water capacity of 6000 mT. The baseline system is optimal relative to technological risk, performance, and product water cost. Subsystems and their interfaces have been defined and product water cost projections made for commercial plants in a range of capacities. Science Applications, Inc. (SAI), subcontractor to Catalytic, had responsibility for the solar power system. This, the final report, summarizes the work performed under the Phase I effort.

The solution of Einstein's field equations with the energy-momentum tensor of a massless scalar field is known as the Fisher solution. It is well known that this solution has a naked singularity due to the ''charge''{Sigma} of the massless scalar field. Here I obtain the radial null geodesic of the Fisher solution and use it to confirm that there is no black hole. In addition, I use the parametrized post-Newtonian formalism to show that the Fisher spacetime predicts the same effects on solar-system experiments as the Schwarzschild one does, as long as we impose a limit on {Sigma}. I show that this limit is not a strong constraint and we can even take values of {Sigma} bigger than M. By using the exact formula of the redshift and some assumptions, I evaluate this limit for the experiment of Pound and Snider [Phys. Rev. 140, B788 (1965)]. It turns out that this limit is {Sigma}<5.8x10{sup 3} m.

The objective of this project was to reduce the cost of racking for PV solar on flat commercial rooftops. Cost reductions would come from both labor savings and material savings related to the installation process. The rack would need to accommodate the majority of modules available on the market. Cascade Engineering has a long history of converting traditional metal type applications over to plastic. Injection molding of plastics have numerous advantages including selection of resin for the application, placing the material exactly where it is needed, designing in features that will speed up the installation process, and weight reduction of the array. A plastic rack would need to meet the requirements of UL2703, Mounting systems, mounting devices, clamping/retention devices, and ground lugs for use with flat-plate photovoltaic modules and panels. Comparing original data to the end of project racking design, racking material costs were reduced 50% and labor costs reduced 64%. The racking product accommodates all 60 and 72 cell panels on the market, meets UL2703 requirements, contributes only 1.3 pounds per square foot of weight to the array, requires little ballast to secure the array, automatically grounds the module when the module is secured, stacks/nests well for shipping/fewer lifts to the roof, provides integrated wire routing, allows water to drain on the roof, and accommodates various seismic roof connections. Project goals were achieved as noted in the original funding application.

The development and testing of a solar powered distillation system are described. The system consists of a parabolic dish collector, a two axis sun tracking stand, sun tracking solar cell system, condenser, fermentation tanks, and continuous distillation still. The assembly instructions for the parabolic dish are included as well as the basic steps to follow in mashing and fermenting of corn meal. 15 figures. (DMC)

In July, we finally visited the last major body of our solarsystem, Pluto. But what lies beyond? The stellar wind from our Sun forms an enormous bubble in interstellar space. This âsphere of our Sun,â or heliosphere, extends far beyond Pluto and forms a protective cocoon that shields us from cosmic radiation. In this talk, we will travel to the edge of the solarsystem, peer into the structure and dynamics of the outer heliosphere as it interacts with the interstellar medium and anticipate the future of the solarsystem as it moves through our galactic neighborhood.

Energy in Grid Integration Systems for Solar Energy DOE to Invest in Grid Integration Systems for Solar Energy August 13, 2008 - 1:00pm Addthis DOE announced on August 12 that it plans to invest up to $24 million over a number of years to develop products that connect solar power systems with the electrical grid in an interactive way. DOE has selected 12 industry teams that will receive $2.9 million in current fiscal year funding to develop conceptual designs and market analyses for such

Princeton Plasma Physics Lab June 17, 2015, 4:15pm to 6:30pm Colloquia MBG Auditorium COLLOQUIUM: Comets and the Origin and Evolution of the SolarSystem Professor David Jewitt University of California - Los Angeles I will give a broad introduction to modern comet science, with a focus on new results and the big picture, relating to the origin and evolution of the solarsystem. Wednesday Colloquium, June 17, 2015, "Comets & the Origin & Evolution of the SolarSystem",

This is the final report of a survey and evaluation of insulation materials for use with components of solar heating and cooling systems. The survey was performed by mailing questionnaires to manufacturers of insulation materials and by conducting an extensive literature search to obtain data on relevant properties of various types of insulation materials. The study evaluated insulation materials for active and passive solar heating and cooling systems and for multifunction applications. Primary and secondary considerations for selecting insulation materials for various components of solar heating and cooling systems are presented.

This report describes the operation and technical performance of the Solar Operational Test Site (OTS 45) at Salt River Project in Phoenix, Arizona, based on the analysis of data collected between April 1981 and March 31, 1982. The following topics are discussed: system description, performance assessment, operating energy, energy savings, system maintenance, and conclusions. The solar energy system at OTS 45 is a hydronic heating and cooling system consisting of 8208 square feet of liquid-cooled flat-plate collectors; a 2500-gallon thermal storage tank; two 25-ton capacity organic Rankine-cycle-engine-assisted water chillers; a forced-draft cooling tower; and associated piping, pumps, valves, controls and heat rejection equipment. The solarsystem has eight basic modes of operation and several combination modes. The system operation is controlled automatically by a Honeywell-designed microprocessor-based control system, which also provides diagnostics. Based on the instrumented test data monitored and collected during the 8 months of the Operational Test Period, the solarsystem collected 1143 MMBtu of thermal energy of the total incident solar energy of 3440 MMBtu and provided 241 MMBtu for cooling and 64 MMBtu for heating. The projected net annual electrical energy savings due to the solarsystem was approximately 40,000 kWh(e).

The Fermi Gamma-ray Space Telescope, launched in June 2008, is an international space mission dedicated to the study of the high-energy gamma rays from the Universe. The main instrument aboard Fermi is the Large Area Telescope (LAT), a pair conversion telescope equipped with the state-of-the art in gamma-ray detectors technology, and operating at energies >30 MeV. During first two months of data taking, Fermi has detected high-energy gamma rays from the quiet Sun and the Moon. This emission is produced by interactions of cosmic rays; by nucleons with the solar and lunar surface, and electrons with solar photons in the heliosphere. While the Moon was detected by EGRET on CGRO with low statistics, Fermi provides high-sensitivity measurements on a daily basis allowing both short- and long-term variability to be studied. Since Galactic cosmic rays are at their maximum flux at solar minimum we expect that the quiescent solar and lunar emission to be a maximum during the period covered by this report. Fermi is the only mission capable of monitoring the Sun at energies above several hundred MeV over the full 24th solar cycle. We present first analysis showing images of Moon and the quiet emission of the solar disk, giving a description of the analysis tools used.

Preliminary comprehensive analyses of quantitative and qualitative employment effects of selected solar and conventional energy systems are presented. It proposes a framework for analyzing the direct, indirect, induced, displacement, disposable income, and qualitative employment effects of alternative energy systems. The analyses examine current research findings on these effects for a variety of solar and conventional energy sources and compare expected employment impacts. In general, solar energy systems have higher direct and indirect employment requirements than do conventional energy systems. In addition, employment displaced from conventional sources and employment effects due to changes in consumers' disposable income are highly significant variables in net employment comparisons. Analyses of the size and location of projected energy developments suggest that dispersed solar energy systems have a more beneficial impact on host communities than do large conventional facilities, regardless of the relative magnitude of employment per unit of energy output.

This manual was prepared primarily for use in conducting a practical training course on the design of solar heating and cooling systems for residential and small office buildings, but may also be useful as a general reference text. The content level is appropriate for persons with different and varied backgrounds, although it is assumed that readers possess a basic understanding of heating, ventilating, and air-conditioning systems of conventional (non-solar) types. This edition is a revision of the manual with the same title, first printed and distributed by the US Government Printing Office in October 1977. The manual has been reorganized, new material has been added, and outdated information has been deleted. Only active solarsystems are described. Liquid and air-heating solarsystems for combined space and service water heating or service water heating are included. Furthermore, only systems with proven experience are discussed to any extent.

A computer simulation method is presented for the design of an electrical auxiliary energy system for passive solar heated structures. The system consists of electrical mats buried in the ground underneath the structure. Energy is stored in the ground during utility off-peak hours and released passively to the heated enclosure. An optimal control strategy is used to determine the system design parameters of depth of mat placement and minimum instaled electrical heating capacity. The optimal control applies combinations of fixed duration energy pulses to the heater, which minimize the room temperature error-squared for each day, assuming advance knowledge of the day's weather. Various realizable control schemes are investigated in an attempt to find a system that approaches the performance of the optimal control system.

The solar energy system, Elcam San Diego, was designed to supply domestic hot water heating for a single family residence located in Encinitas, California. The contents of this document have been divided into System Description, Performance Assessment, Operating Energy, Energy Savings, Maintenance and Summary and Conclusions. The system is a Sunspot two tank cascade type, where solar energy is supplied to either a 66 gallon preheat tank (solar storage) or a 40 gallon domestic hot water tank. Water is pumped directly from one of the two tanks, through the 65 square feet collector array and back into the same tank. Freeze protection is provided by automatically circulating hot water from the hot water tank through the collectors and exposed plumbing when freezing conditions exist. Auxiliary energy is supplied by natural gas. The Elcam San Diego solar energy system has three modes of operation.

Sutton, Stephen R. [University of Chicago, Chicago, Illinois, United States

2010-01-08

Sample-return missions and natural collection processes have provided us with a surprisingly extensive collection of matter from SolarSystem bodies other than the Earth. These collections include samples from the Moon, Mars, asteroids, interplanetary dust, and, recently, from the Sun (solar wind) and a comet. This presentation will describe some of these materials, how they were collected, and what we have learned from them. Synchrotron radiation analyses of these materials are playing an increasingly valuable role in unraveling the histories and properities of the parent SolarSystem bodies.

The purpose of this article is to present a method of selecting hydrogen-production systems using the electric power obtained in photovoltaic systems, and as a selecting method, we suggest the use of the Advanced Multi-Criteria Analysis based on the FRISCO formula. According to the case study on how to select the solar radiation hydrogen production system, the most convenient alternative is the alternative A4, namely the technical solution involving a hydrogen production system based on the electrolysis of water vapor obtained with concentrated solar thermal systems and electrical power obtained using concentrating photovoltaic systems.

The diurnal nature of solar power is made uncertain by variable cloud cover and the influence of atmospheric conditions on irradiance scattering processes. Its forecasting has become increasingly important to the unit commitment and dispatch process for efficient scheduling of generators in power system operations. This presentation is an overview of a study that examines the value of improved solar forecasts on Bulk Power System Operations.

Spearfish High School in South Dakota contains 43,000 square feet of conditioned space. Its active solar energy system is designed to supply 57% of the space heating and 50% of the hot water demand. The system is equipped with 8034 square feet of flat plate collectors, 4017 cubic feet of rock bin sensible heat storage, and auxiliary equipment including 8 heat pumps, 6 of which are solar supplied and instrumented, air conditioning units, and natural-gas-fired boilers. Performance data are given for the system including the solar fraction, solar savings ratio, conventional fuel savings, system performance factor and solarsystem coefficient of performance. Insolation, solar energy utilization and operation data are also given. The performance of the collector, storage, domestic hot water and space heating subsystems, the operating energy, energy savings, and weather conditions are also evaluated. Appended are a system description, performance evaluation techniques and equations, site history, long-term weather data, sensor technology, and typical monthly data. (LEW)

This report identifies ares on the five major islands (Oahu, Maui, Molakai, Hawaii, and Kauai) that have the potential for concentrating solar thermal applications. The locations are based on existing solar insolation (mostly global and some direct normal) data, other meteorological information, land use, potential end-use, and existing facilities. These areas are: - Western coast of Oahu, especially near Kahe Point - Maui plains area - South-Central Molokai - Kona coast of the Big Island, especially Natural Energy Laboratory of Hawaii - Western and southern areas of Kauai. Monitoring stations are recommended at some of these sites to obtain direct normal insolation data for future evaluation.

Disclosed is a solar power tower heliostat alignment system and method that includes a solar power tower with a focal area, a plurality of heliostats that each reflect sunlight towards the focal area of the solar power tower, an off-focal area location substantially close to the focal area of the solar power tower, a communication link between the off-focal area location and a misaligned heliostat, and a processor that interprets the communication between the off-focal area location and the misaligned heliostat to identify the misaligned heliostat from the plurality of heliostats and that determines a correction for the identified misaligned heliostat to realign the misaligned heliostat to reflect sunlight towards the focal area of the solar power tower.

A heliostat for a solar receiver system comprises an improved drive and control system for the heliostat reflector assembly. The heliostat reflector assembly is controllably driven in a predetermined way by a light-weight drive system so as to be angularly adjustable in both elevation and azimuth to track the sun and efficiently continuously reflect the sun's rays to a focal zone, i.e., heat receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The improved drive system includes linear stepping motors which comprise low weight, low cost, electronic pulse driven components. One embodiment comprises linear stepping motors controlled by a programmed, electronic microprocessor. Another embodiment comprises a tape driven system controlled by a position control magnetic tape.

This fact sheet presents highlights from the Best Practices Handbook for the Collection and Use of Solar Resource Data for Solar Energy Applications, which provides detailed information about solar resource data and the resulting data products needed for planning each stage of large concentrating solar power systems, from initial site selection to system operations.

The production and storage of thermochemical energy is a possible route to increase capacity factors and reduce the Levelized Cost of Electricity from concentrated solar power generation systems. In this paper, we present the results of cycle evaluations for various thermochemical cycles, including a well-documented ammonia closed-cycle along with open- and closed-cycle versions of hydrocarbon chemical reactions. Among the available reversible hydrocarbon chemical reactions, catalytic reforming-methanation cycles are considered; specifically, various methane-steam reforming cycles are compared to the ammonia cycle. In some cases, the production of an intermediate chemical, methanol, is also included with some benefit being realized. The best case, based on overall power generation efficiency and overall plant capacity factor, was found to be an open cycle including methane-steam reforming, using concentrated solar energy to increase the chemical energy content of the reacting stream, followed by combustion to generate heat for the heat engine.

This document is the sixth volume of the Building America Best Practices Series. It presents information that is useful throughout the United States for enhancing the energy efficiency practices in the specific climate zones that are presented in the first five Best Practices volumes. It provides an introduction to current photovoltaic and solar thermal building practices. Information about window selection and shading is included.

Linear concentrating solar power (CSP) collectors capture the sun's energy with large mirrors that reflect and focus the sunlight onto a linear receiver tube. The receiver contains a fluid that is heated by the sunlight and then used to heat a traditional power cycle that spins a turbine that drives a generator to produce electricity.

The three large solar particle events, beginning on October 19, 1989 and lasting approximately six days, were characterized by high fluences of solar protons and heavy ions at 1 AU. During these events, an abnormally large number of upsets (243) were observed in the random access memory of the attitude control system (ACS) control processing electronics (CPE) on-board the geosynchronous TDRS-1 (Telemetry and Data Relay Satellite). The RAM unit affected was composed of eight Fairchild 93L422 memory chips. The Galileo spacecraft, launched on October 18, 1989 (one day prior to the solar particle events) observed the fluxes of heavy ions experienced by TDRS-1. Two solid-state detector telescopes on-board Galileo, designed to measure heavy ion species and energy, were turned on during time periods within each of the three separate events. The heavy ion data have been modeled and the time history of the events reconstructed to estimate heavy ion fluences. These fluences were converted to effective LET spectra after transport through the estimated shielding distribution around the TDRS-1 ACS system. The number of single event upsets (SEU) expected was calculated by integrating the measured cross section for the Fairchild 93L422 memory chip with average effective LET spectrum. The expected number of heavy ion induced SEU`s calculated was 176. GOES-7 proton data, observed during the solar particle events, were used to estimate the number of proton-induced SEU`s by integrating the proton fluence spectrum incident on the memory chips, with the two-parameter Bendel cross section for proton SEU`s. The proton fluence spectrum at the device level was gotten by transporting the protons through the estimated shielding distribution. The number of calculated proton-induced SEU`s was 72, yielding a total of 248 predicted SEU`s, very close to the 243 observed SEU`s.

This document introduces the Energy Departmentâs new Guide to Community Shared Solar: Utility, Private, and Nonprofit Project Development. The guide is designed to help those who want to develop community shared solar projectsâfrom community organizers and advocates to utility managers and government officialsânavigate the process of developing shared systems, from early planning to implementation.

A solar light distribution system includes a solar light concentrator that is affixed externally to a light transfer tube. Solar light waves are processed by the concentrator into a collimated beam of light, which is then transferred through a light receiving port and into the light transfer tube. A reflector directs the collimated beam of light through the tube to a light distribution port. The interior surface of the light transfer tube is highly reflective so that the light transfers through the tube with minimal losses. An interchangeable luminaire is attached to the light distribution port and distributes light inside of a structure. A sun tracking device rotates the concentrator and the light transfer tube to optimize the receiving of solar light by the concentrator throughout the day. The system provides interior lighting, uses only renewable energy sources, and releases no carbon dioxide emissions into the atmosphere.

A solar light distribution system includes a solar light concentrator that is affixed externally to a light transfer tube. Solar light waves are processed by the concentrator into a collimated beam of light, which is then transferred through a light receiving port and into the light transfer tube. A reflector redirects the collimated beam of light through the tube to a light distribution port. The interior surface of the light transfer tube is highly reflective so that the light transfers through the tube with minimal losses. An interchangeable luminaire is attached to the light distribution port and provides light inside of a structure. A sun tracking device rotates the concentrator and the light transfer tube to optimize the receiving of solar light by the concentrator throughout the day. The system provides interior lighting that uses only renewable energy sources, and releases no carbon dioxide emissions into the atmosphere.

Department of Energy Thermal Storage System for Solar Plants Project Profile: High-Efficiency Thermal Storage System for Solar Plants SENER logo SENER, under the Baseload CSP FOA, aimed to develop a highly efficient, low-maintenance and economical thermal energy storage (TES) system using solid graphite modular blocks for CSP plants. Approach Graphic of a rectangle shape to the left of a row or smaller rectangles stacked in two rows. The main objective was to evaluate a TES system able to

This project addresses the problem of lower solar conversion efficiency and waste in the typical solar cell manufacturing process. The work from the proposed development will lead toward developing a system which should be able to increase solar panel conversion efficiency by an additional 12-15% resulting in lower cost panels, increased solar technology adoption, reduced carbon emissions and reduced dependency on foreign oil. All solar cell manufacturing processes today suffer from manufacturing inefficiencies that currently lead to lower product quality and lower conversion efficiency, increased product cost and greater material and energy consumption. This results in slower solar energy adoption and extends the time solar cells will reach grid parity with traditional energy sources. The thin film solar panel manufacturers struggle on a daily basis with the problem of thin film thickness non-uniformity and other parameters variances over the deposited substrates, which significantly degrade their manufacturing yield and quality. Optical monitoring of the thin films during the process of the film deposition is widely perceived as a necessary step towards resolving the non-uniformity and non-homogeneity problem. In order to enable the development of an optical control system for solar cell manufacturing, a new type of low cost optical sensor is needed, able to acquire local information about the panel under deposition and measure its local characteristics, including the light scattering in very close proximity to the surface of the film. This information cannot be obtained by monitoring from outside the deposition chamber (as traditional monitoring systems do) due to the significant signal attenuation and loss of its scattering component before the reflected beam reaches the detector. In addition, it would be too costly to install traditional external in-situ monitoring systems to perform any real-time monitoring over large solar panels, since it would require

The system design for a future commercial solar energy brackish water desalination plant is described. Key features of the plant are discussed along with its configuration selection rationale, design objectives, operation, and performance. The water treatment technology used in the plant is ion exchange pretreatment and single stage reverse osmosis desalination utilizing high-flux membranes. Electrical power needed for plant operation is produced by a solar energy system, which is based on the Brayton cycle having air as the working fluid. Primary solarsystem components are: heliostat field, central cavity-tube receiver, receiver support tower, thermal energy storage, and a commercial gas turbine generator set. The thermal energy storage subsystem is of the sensible heat brick type and provides a capability for continuous day/night power generation during most weather conditions. This system design was selected in a study of various system alternatives and their life cycle product water costs for a representative site in western Texas.

This document is the Final Report of the Solar Energy System located at the Wilmington, Swim School, New Castle, Delaware. This active solarsystem is composed of 2,700 square feet of Revere liquid flat plate collectors piped to a 2,800 gallon concrete storage tank located below ground near the building. A micro-computer based control system selects the optimal applications of the stored energy among space, domestic water and pool alternatives. The controlled logic is planned for serving the heat loads in the following order: space heat-new addition, domestic water-entire facility, and pool heating-entire facility. A modified trombe wall passive operation the active system will bypass the areas being served passively. The system was designed for a 40 percent heating and a 30 percent hot water solar contribution.

| Argonne-Northwestern National Laboratory 1: Molecules, Materials, and Systems for Solar Fuels Home > Research > Subtask 1 The above figure depicts an iridium catalyst used for water splitting. The above figure depicts an iridium catalyst used for water splitting. The greatest challenge facing the development of solar fuels is efficient fuel production at acceptable rates and driving forces. The ANSER Center is confronting this challenge by taking a hierarchical approach to designing,

This paper discusses how concerted efforts to monitor the effects of solar magnetic disturbances (SMD) in the United States began anew after the March 13, 1989, disturbance. Previous efforts to monitor SMD were undertaken in the early 1970s. This earlier program monitored 64 different locations throughout the continental United States during the period from March 1969 to September 1972. This work was done during sunspot cycle 21 involving monitoring, effects, and mitigation of geomagnetically induced currents (GIC).

Experimental performance data from dish/Stirling system testing can be analyzed to generate a system performance model. An approach to developing an experimentally based performance model of a dish/Stirling system is given. Two methods for analyzing the experimental data are described. To provide information that will permit comparison of dish/Stirling systems, it is necessary to define many of the details involved in calculating system performance data such as the net system output and systemsolar-to-electric efficiency. This paper describes a set of guidelines for these calculations, based on past experience, especially with the Vanguard dish/Stirling system. Also presented are a set of rating conditions at which a maximum value for system efficiency can be calculated. Comparison between systems of their rated peak solar-to-electric efficiency is made possible when these rating conditions are in common use by manufacturers and testing agencies.

AstroPower, Royal Group Technologies, and Solar Design Associates are jointly developing an integrated photovoltaic roofing system for residential and light commercial building applications. This family of products will rely heavily on the technological development of a roofing tile made from recycled plastic and innovative module fabrication and encapsulation processes in conjunction with an advanced Silicon-Film{trademark} solar cell product. This solar power generating roofing product is presently being referred to as the SolarTile. A conceptual drawing of the solar roofing tile is shown. The SolarTile will be integrated with non-solar tiles in a single roof installation permitting ease of assembly and the ability to use conventional roofing techniques at ridges, valleys, and eaves. The Phase 1 effort included tasks aimed at the development of the proposed product concept; product manufacturing or fabrication, and installation cost estimates; business planning; and a market assessment of the proposed product, including target selling prices, target market sectors, size estimates for each market sector, and planned distribution mechanisms for market penetration. Technical goals as stated in the Phase 1 proposal and relevant progress are reported.

This specification defines the characteristics, design and environmental requirements, and economic data for a solar central receiver system integrated with a cogeneration facility for copper smelting. The added solar capacity will supply process heat to an existing copper smelting flash furnace of Finnish design as well as providing for the cogeneration of electricity by an added gas turbine system. Heat storage to accommodate periods of low solar insolation is accomplished by the innovative utilization of copper slag in a thermal energy storage system. This specification is limited (1) to those portions of the plant to be added or modified in order to accomplish the proposed solar retrofit, and (2) by the conceptual design nature of the contracted study. Section 1 of this specification describes the proposed modifications to existing site conditions and facilities, and the nomenclature used. Section 2 provides a listing of applicable standards and codes, publications, reference documentation, and regulatory information. Design and performance requirements to be met by this solar cogeneration facility are outlined in Section 3, and the environmental criteria applicable to the plant are addressed in Section 4. The solar cogeneration facility's characteristics and performance data are specified in Section 5, along with the plant cost and economic data. Simulation models are also described. Appendix B presents site facility information; Appendix C covers the determination of the physical and chemical properties of copper smelter slag; Appendix D presents estimating backup sheets.

A system and method for optimizing at least one mirror of at least one CSP system is provided. The system has a screen for displaying light patterns for reflection by the mirror, a camera for receiving a reflection of the light patterns from the mirror, and a solar characterization tool. The solar characterization tool has a characterizing unit for determining at least one mirror parameter of the mirror based on an initial position of the camera and the screen, and a refinement unit for refining the determined parameter(s) based on an adjusted position of the camera and screen whereby the mirror is characterized. The system may also be provided with a solar alignment tool for comparing at least one mirror parameter of the mirror to a design geometry whereby an alignment error is defined, and at least one alignment unit for adjusting the mirror to reduce the alignment error.

The long-term field performance of the installed system and technical contributions to the definition of techniques and requirements for solar energy system design are reported. The Solar Energy System was designed by Solaron Corporation, Denver, Colorado, to provide an 1840 square foot floor area with space heating and domestic hot water (DHW) for a dual-level single family residence in Akron, Ohio. The Solar Energy System uses air as the heat transport medium, has a 546 square foot flat plate collector array subsystem, a 270 cubic foot rock thermal storage bin subsystem, a domestic hot water preheat tank, pumps, controls and transport lines. The auxiliary space heating subsystem is an air to liquid heat pump coupled with a 1000 gallon water storage tank. Electricity provides auxiliary energy for both space heating and DHW subsystems.

A new method of predicting the solar heat gain through complex fenestration systems involving nonspecular layers such as shades or blinds has been examined in a project jointly sponsored by ASHRAE and DOE. In this method, a scanning radiometer is used to measure the bidirectional radiative transmittance and reflectance of each layer of a fenestration system. The properties of systems containing these layers are then built up computationally from the measured layer properties using a transmission/multiple-reflection calculation. The calculation produces the total directional-hemispherical transmittance of the fenestration system and the layer-by-layer absorptances. These properties are in turn combined with layer-specific measurements of the inward-flowing fractions of absorbed solar energy to produce the overall solar heat gain coefficient. This method has been used to determine the solar heat gain coefficient of a double-glazed window with an interior white shade. The resulting solar heat gain coefficient was compared to a direct measurement of the same system using the Mobile Window Thermal Test (MoWiTT) Facility for measuring window energy performance, and the two results agreed. This represents the first in a series of planned validations and applications of the new method.

The computational methods for calculating the properties of glazing systems containing shading from the properties of their components have been developed, but the measurement standards and property data bases necessary to apply them have not. It is shown that with a drastic simplifying assumption these methods can be used to calculate systemsolar-optical properties and solar heat gain coefficients for arbitrary glazing systems, while requiring limited data about the shading. Detailed formulas are presented, and performance multipliers are defined for the approximate treatment of simple glazings with shading. As higher accuracy is demanded, the formulas become very complicated.

This fact sheet describes the collaboration between NREL, SolarCity, and the Hawaiian Electric Companies at the Energy Systems Integration Facility (ESIF) to address the safety, reliability, and stability challenges of interconnecting high penetrations of distributed photovoltaics with the electric power system.

Distributed Solar PV systems have the potential of increasing the grid's resiliency to unforeseen events, such as extreme weather events and attacks. This paper presents the role that distributed PV can play in electric grid resiliency, introduces basic system design requirements and options, and discusses the regulatory and policy options for supporting the use of distributed PV for the purpose of increased electricity resiliency.

This seminar material was developed primarily to provide solar photovoltaic (PV) applied engineering technology to the Federal community. An introduction to photoconductivity, semiconductors, and solar photovoltaic cells is included along with a demonstration of specific applications and application identification. The seminar details general systems design and incorporates most known information from industry, academia, and Government concerning small solar cell power system design engineering, presented in a practical and applied manner. Solar PV power system applications involve classical direct electrical energy conversion and electric power system analysis and synthesis. Presentations and examples involve a variety of disciplines including structural analysis, electric power and load analysis, reliability, sizing and optimization; and, installation, operation and maintenance. Four specific system designs are demonstrated: water pumping, domestic uses, navigational and aircraft aids, and telecommunications. All of the applications discussed are for small power requirement (under 2 kilowatts), stand-alone systems to be used in remote locations. Also presented are practical lessons gained from currently installed and operating systems, problems at sites and their resolution, a logical progression through each major phase of system acquisition, as well as thorough design reviews for each application.

Direct steam generation (DSG) in parabolic trough collectors causes an increase to competitiveness of solar thermal power plants (STPP) by substitution of oil with direct steam generation that results in lower investment and operating costs. In this study the integrated solar combined cycle system with DSG technology is introduced and techno-economic assessment of this plant is reported compared with two conventional cases. Three considered cases are: an integrated solar combined cycle system with DSG technology (ISCCS-DSG), a solar electric generating system (SEGS), and an integrated solar combined cycle system with HTF (heat transfer fluid) technology (ISCCS-HTF). This study shows that levelized energy cost (LEC) for the ISCCS-DSG is lower than the two other cases due to reducing O and M costs and also due to increasing the heat to electricity net efficiency of the power plant. Among the three STPPs, SEGS has the lowest CO{sub 2} emissions, but it will operate during daytime only. (author)

Data are provided on 32 solar heating sites in the National Solar Data Network (NSDN). Of these, comprehensive data are included for 14 sites which cover a range of system types and solar applications. A brief description of the remaining sites is included along with system problems experienced which prevented comprehensive seasonal analyses. Tables and discussions of individual site parameters such as collector areas, storage tank sizes, manufacturers, building dimensions, etc. are provided. Tables and summaries of 1980-1981 heating season data are also provided. Analysis results are presented in graphic form to highlight key summary information. Performance indices are graphed for two major groups of collectors - liquid and air. Comparative results of multiple NSDN systems' operation for the 1980-1981 heating season are summarized with discussions of specific cases and conclusions which may be drawn from the data. (LEW)

This guide is was written by PNNL for the US Department of Energy's Building America program to provide information for residential production builders interested in building near zero energy homes. The guide provides indepth descriptions of various roof-top photovoltaic power generating systems for homes. The guide also provides extensive information on various designs of solar thermal water heating systems for homes. The guide also provides construction company owners and managers with an understanding of how solar technologies can be added to their homes in a way that is cost effective, practical, and marketable. Twelve case studies provide examples of production builders across the United States who are building energy-efficient homes with photovoltaic or solar water heating systems.

This document discusses improving system operations with forecasting and solar generation. By integrating variable renewable energy (VRE) forecasts into system operations, power system operators can anticipate up- and down-ramps in VRE generation in order to cost-effectively balance load and generation in intra-day and day-ahead scheduling. This leads to reduced fuel costs, improved system reliability, and maximum use of renewable resources.

The purpose of this work consists in thermodynamic modeling of hybrid photovoltaic-thermal (PV/T) solarsystems, pursuing a modular strategy approach provided by Simulink/Matlab. PV/T solarsystems are a recently emerging solar technology that allows for the simultaneous conversion of solar energy into both electricity and heat. This type of technology present some interesting advantages over the conventional ''side-by-side'' thermal and PV solarsystems, such as higher combined electrical/thermal energy outputs per unit area, and a more uniform and aesthetical pleasant roof area. Despite the fact that early research on PV/T systems can be traced back to the seventies, only recently it has gained a renewed impetus. In this work, parametric studies and annual transient simulations of PV/T systems are undertaken in Simulink/Matlab. The obtained results show an average annual solar fraction of 67%, and a global overall efficiency of 24% (i.e. 15% thermal and 9% electrical), for a typical four-person single-family residence in Lisbon, with p-Si cells, and a collector area of 6 m{sup 2}. A sensitivity analysis performed on the PV/T collector suggests that the most important variable that should be addressed to improve thermal performance is the photovoltaic (PV) module emittance. Based on those results, some additional improvements are proposed, such as the use of vacuum, or a noble gas at low-pressure, to allow for the removal of PV cells encapsulation without air oxidation and degradation, and thus reducing the PV module emittance. Preliminary results show that this option allows for an 8% increase on optical thermal efficiency, and a substantial reduction of thermal losses, suggesting the possibility of working at higher fluid temperatures. The higher working temperatures negative effect in electrical efficiency was negligible, due to compensation by improved optical properties. The simulation results are compared with experimental data obtained from other authors

We propose a system for forecasting short-term solar irradiance based on multiple total sky imagers (TSIs). The system utilizes a novel method of identifying and tracking clouds in three-dimensional space and an innovative pipeline for forecasting surface solar irradiance based on the image features of clouds. First, we develop a supervised classifier to detect clouds at the pixel level and output cloud mask. In the next step, we design intelligent algorithms to estimate the block-wise base height and motion of each cloud layer based on images from multiple TSIs. Thus, this information is then applied to stitch images together into larger views, which are then used for solar forecasting. We examine the systems ability to track clouds under various cloud conditions and investigate different irradiance forecast models at various sites. We confirm that this system can 1) robustly detect clouds and track layers, and 2) extract the significant global and local features for obtaining stable irradiance forecasts with short forecast horizons from the obtained images. Finally, we vet our forecasting system at the 32-megawatt Long Island Solar Farm (LISF). Compared with the persistent model, our system achieves at least a 26% improvement for all irradiance forecasts between one and fifteen minutes.

To permit an economic evaluation of solar industrial process heat systems, a methodology was developed to determine the annual required revenue and the internal rate of return. First, a format is provided to estimate the solarsystem's installed cost, annual operating and maintenance expenses, and net annual solar energy delivered to the industrial process. Then an expression is presented that gives the annual required revenue and the price of solar energy. The economic attractiveness of the potential solar investment can be determined by comparing the price of solar energy with the price of fossil fuel, both expressed in levelized terms. This requires calculation of the internal rate of return on the solar investment or, in certain cases, the growth rate of return.

The post Newtonian parameter is considered in the chameleon-Brans-Dicke model. In the first step, the general form of this parameter and also effective gravitational constant is obtained. An arbitrary function for f({Phi}), which indicates the coupling between matter and scalar field, is introduced to investigate validity of solarsystem constraint. It is shown that the chameleon-Brans-Dicke model can satisfy the solarsystem constraint and gives us an {omega} parameter of order 10{sup 4}, which is in comparable to the constraint which has been indicated in [19].

There are many difficulties limiting the further development of monolithic multi-junction solar cells, such as the growth of lattice-mismatched material and the current matching constraint. As an alternative approach, the light-splitting photovoltaic system is investigated intensively in different aspects, including the energy loss mechanism and the choice of energy bandgaps of solar cells. Based on the investigation, a two-dual junction system has been implemented employing lattice-matched GaInP/GaAs and InGaAsP/InGaAs cells grown epitaxially on GaAs and InP substrates, respectively. (author)

Beyond | Department of Energy Demonstrates Production of Fuel for Missions to the SolarSystem and Beyond U.S. Demonstrates Production of Fuel for Missions to the SolarSystem and Beyond December 22, 2015 - 10:09am Addthis News Media Contact (202) 586-4940 DOENews@hq.doe.gov The first U.S. production in nearly 30 years of a specialized fuel to power future deep space missions has been completed by researchers at the Department of Energy's Oak Ridge National Laboratory (ORNL) in Tennessee.

The solar heating and cooling system installed at the headquarters of Citizens Mutual Savings Association in Leavenworth, Kansas, is described in detail. The project is part of the U.S. Department of Energy's solar demonstration program and became operational in March, 1979. The designer was TEC, Inc. Consulting Engineers, Kansas City, Missouri and contractor was Norris Brothers, Inc., Lawrence, Kansas. The solarsystem is expected to furnish 90 percent of the overall heating load, 70 percent of the cooling load and 100 percent of the domestic hot water load. The building has two floors with a total of 12,000 square feet gross area. The system has 120 flat-plate liquid solar panels with a net area of 2200 square feet. Five, 3-ton Arkla solar assisted absorption units provide the cooling, in conjunction with a 3000 gallon chilled water storage tank. Two, 3000 gallon storage tanks are provided with one designated for summer use, whereas both tanks are utilized during winter.

Sandia National Laboratories, Albuquerque (SNLA), is currently conducting a program to predict the performance and measure the characteristics of commercially available solar collectors that have the potential for use in industrial process heat and enhanced oil recovery applications. The thermal performance predictions for the Solar Kinetics solar line-focusing parabolic trough collector for five cities in the US are presented. (WHK)

This is the final report covering a June 2004 through May 2009 grant to support the certification of solar thermal collectors and systems. The Solar Rating and Certification Corporation (SRCC) has developed and maintained minimum standards and performance tests for solar water heating components and systems since 1980. The objective of this project was to continue the SRCC certification program and implement enhancements to the standards and test methods used to determine product durability and calculate performance ratings. This objective was met by supporting the operation of the certification programs and by performing five additional technical tasks that addressed specific areas that were identified for enhancement. Statistics on certifications and lists of issues that were addressed are reported.

Dish/Stirling is a solar thermal electric technology which couples parabolic, point-focusing solar collectors and heat engines which employ the Stirling thermodynamic cycle. Since the late 1970s, the development of Dish/Stirling systems intended for commercial use has been in progress in Germany, Japan, and the US. In the next several years it is expected that one or more commercial systems will enter the market place. This paper provides a general overview of this emerging technology, including: a description of the fundamental principles of operation of Dish/Stirling systems; a presentation of the major components of the systems (concentrator, receiver, engine/alternator, and controls); an overview of the actual systems under development around the world, with a discussion of some of the technical issues and challenges facing the Dish/Stirling developers. A brief discussion is also presented of potential applications for small Dish/Stirling systems in northern Mexico.

Abstract-- In this paper, the ability of the Nevada (NV) Energy generation fleet to meet its system balancing requirements under different solar energy penetration scenarios is studied. System balancing requirements include capacity, ramp rate, and ramp duration requirements for load following and regulation. If, during some operating hours, system capability is insufficient to meet these requirements, there is certain probability that the balancing authoritys control and reliability performance can be compromised. These operating hours are considered as challenging hours. Five different solar energy integration scenarios have been studied. Simulations have shown that the NV Energy system will be potentially able to accommodate up to 942 MW of solar photovoltaic (PV) generation. However, the existing generation scheduling procedure should be adjusted to make it happen. Fast-responsive peaker units need to be used more frequently to meet the increasing ramping requirements. Thus, the NV Energy system operational cost can increase. Index TermsSolar Generation, Renewables Integration, Balancing Process, Load Following, Regulation.

We propose a system for forecasting short-term solar irradiance based on multiple total sky imagers (TSIs). The system utilizes a novel method of identifying and tracking clouds in three-dimensional space and an innovative pipeline for forecasting surface solar irradiance based on the image features of clouds. First, we develop a supervised classifier to detect clouds at the pixel level and output cloud mask. In the next step, we design intelligent algorithms to estimate the block-wise base height and motion of each cloud layer based on images from multiple TSIs. Thus, this information is then applied to stitch images together into larger views, which are then used for solar forecasting. We examine the systemâs ability to track clouds under various cloud conditions and investigate different irradiance forecast models at various sites. We confirm that this system can 1) robustly detect clouds and track layers, and 2) extract the significant global and local features for obtaining stable irradiance forecasts with short forecast horizons from the obtained images. Finally, we vet our forecasting system at the 32-megawatt Long Island Solar Farm (LISF). Compared with the persistent model, our system achieves at least a 26% improvement for all irradiance forecasts between one and fifteen minutes.

The Wormser Solar Energy System located in a four unit townhouse apartment (5400 square feet) in Columbia, South Carolina was designed to provide 50% of the hot water and 70% of the space heating by the Wormser Scientific Corporation, Stamford, Connecticut. The Solar Energy System consists of 266 ft/sup 2/ of pyramidal optics, flat-plate liquid collectors, a solar window area of 1152 ft/sup 2/, a 2500 gallon thermal water storage tank, an energy transport system (water), heat exchangers, pumps, controls and four domestic hot water (DHW) tanks. Electrical elements in each domestic hot water tank provide necessary auxiliary energy for hot water. Four multifunctional heat pumps, supplied with solar heated water provide space heating energy to the apartments, collector freeze protection is provided through the location of the collectors inside the attic. The system with six modes of operation became oprational in February 1978. The following topics are discussed: system description, performance assessment, operating energy, energy savings, maintenance, summary and conclusions.

We propose a system for forecasting short-term solar irradiance based on multiple total sky imagers (TSIs). The system utilizes a novel method of identifying and tracking clouds in three-dimensional space and an innovative pipeline for forecasting surface solar irradiance based on the image features of clouds. First, we develop a supervised classifier to detect clouds at the pixel level and output cloud mask. In the next step, we design intelligent algorithms to estimate the block-wise base height and motion of each cloud layer based on images from multiple TSIs. Thus, this information is then applied to stitch images together intomoreÂ Â» larger views, which are then used for solar forecasting. We examine the systemâs ability to track clouds under various cloud conditions and investigate different irradiance forecast models at various sites. We confirm that this system can 1) robustly detect clouds and track layers, and 2) extract the significant global and local features for obtaining stable irradiance forecasts with short forecast horizons from the obtained images. Finally, we vet our forecasting system at the 32-megawatt Long Island Solar Farm (LISF). Compared with the persistent model, our system achieves at least a 26% improvement for all irradiance forecasts between one and fifteen minutes.Â«Â less

The analysis used is based on instrumented system data monitored and collected for at least one full season of operation. The objective of the analysis is to report the long-term field performance of the installed system and to make technical contributions to the definition of techniques and requirements for solar energy system design. The solarsystem, Elcam-Tempe, was designed to supply commercial domestic hot water heating systems that utilize two, four by eight foot flat plate collectors to heat water in a fifty-two gallon preheat tank or a fifty-two gallon domestic hot water (DHW) tank. The DHW tank provides hot water to the Agriculture Department residence at Arizona State University. The system uses an automatic cascade control system to control three independent actuators, the coolant circulation pump, the cascade valve, and the electric heating element. The system provides freeze protection by automatically circulating hot water from the hot water tank through the collectors when the collector outlet temperature is below a specified value. The building is a single story residence located at the agriculture experiment farm of the Arizona State University. The Elcam-Tempe Solar Energy System has four modes of operation.

The purpose of this PTS is to collaboratively leverage the collective resources at General Electric Global Research (GEGRC) and National Renewable Energy Laboratories (NREL) in the areas of concentrating solar power hybrid systems to advance state-of-the-art concentrating solar and conventional power generation system integration.

Application of an active hydronic domestic hot water and space heating solarsystem for the Central Food Services Building is discussed. The closed-loop drain-back system is described as offering dependability of gravity drain-back freeze protection, low maintenance, minimal costs, and simplicity. The system features an 840 square-foot collector and storage capacity of 1550 gallons. The acceptance testing and the predicted system performance data are briefly described. Solar performance calculations were performed using a computer design program (FCHART). Bidding, costs, and economics of the system are reviewed. Problems are discussed and solutions and recommendations given. An operation and maintenance manual is given in Appendix A, and Appendix B presents As-built Drawings. (MCW)

A freeze protection system allows the working fluid contained in the communicating tubes of the solar collector to drain from both the input and output tubes of the collector when a first predetermined temperature of the working fluid is detected and to fill the collector via both the input and output tubes when a second predetermined temperature is detected.

This model bylaw was established to assist cities and towns throughout Massachusetts in establishing reasonable standards to facilitate the development of small, medium, and large-scale ground mounted or roof mounted solarsystems. Municipalities are encouraged to use this bylaw to amend existing portions of local regulations with the help of municipal counsel.

We use seven year's worth of observations from the Catalina Sky Survey and the Siding Spring Survey covering most of the northern and southern hemisphere at galactic latitudes higher than 20Â° to search for serendipitously imaged moving objects in the outer solarsystem. These slowly moving objects would appear as stationary transients in these fast cadence asteroids surveys, so we develop methods to discover objects in the outer solarsystem using individual observations spaced by months, rather than spaced by hours, as is typically done. While we independently discover eight known bright objects in the outer solarsystem, the faintest having V=19.8Â±0.1, no new objects are discovered. We find that the survey is nearly 100% efficient at detecting objects beyond 25 AU for VâČ19.1 (VâČ18.6 in the southern hemisphere) and that the probability that there is one or more remaining outer solarsystem object of this brightness left to be discovered in the unsurveyed regions of the galactic plane is approximately 32%.

Items are listed that should be considered in each aspect of the design of a solar industrial process heat system. The collector technologies covered are flat-plate, evacuated tube, and line focus. Qualitative design considerations are stressed rather than specific design recommendations. (LEW)

The mountain paradise of Park City, Utah - best known for its sensational skiing and annual Sundance Film Festival - is quickly becoming a shining example of environmental sustainability. The cityâs latest green endeavor: an 18 kW solar energy system on top of the historic Marsac Building.

Residential and commercial end users of electricity who want to generate electricity using on-site solar photovoltaic (PV) systems face challenging initial and O&M costs. The third-party ownership power purchase agreement (PPA) finance model addresses these and other challenges. It allows developers to build and own PV systems on customers? properties and sell power back to customers. However, third-party electricity sales commonly face five regulatory challenges. The first three challenges involve legislative or regulatory definitions of electric utilities, power generation equipment, and providers of electric services. These definitions may compel third-party owners of solar PV systems to comply with regulations that may be cost prohibitive. Third-party owners face an additional challenge if they may not net meter, a practice that provides significant financial incentive to owning solar PV systems. Finally, municipalities and cooperatives worry about the regulatory implications of allowing an entity to sell electricity within their service territories. This paper summarizes these challenges, when they occur, and how they have been addressed in five states. This paper also presents alternative to the third-party ownership PPA finance model, including solar leases, contractual intermediaries, standardized contract language, federal investment tax credits, clean renewable energy bonds, and waived monopoly powers.

This document is a scan of the resolution, dated July 26, 2011, for the approval of the City of Knoxville, Tennessee to use $250,000 of EECBG funding for finding innovative financing mechanisms for a planned installation of a 90-kW solar PV system.

The five Solar Electric Generating Systems (SEGS) at Kramer Junction, California, now have nearly 30 years of cumulative operating experience. These 30 MW plants employ parabolic trough technology originally deployed by LUZ International in the late 1980`s and are now managed, operated and maintained by the Kramer Junction Company. In this paper, Sandia National Laboratories performed an analysis of the annual energy production from the five plants. Annual solar-to-electric conversion efficiencies are calculated and the major factors that influenced the results are presented. The generally good efficiencies are primarily attributed to the excellent equipment availabilities achieved at all plants.

An outline of possibilities for effective use of PV/T collectors with a Solar Assisted Heat Pump is given. A quantitative analysis of the performance and cost of the various configurations as a function of regional climates, using up-to-date results from solar heat pump and PV/T collector studies, will be required for more definitive assessment; and it is recommended that these be undertaken in the PV/T Program. Particular attention should be paid to development of high performance PV/T collectors, matching of heat pump electrical system to PV array and power conditioning characteristics, and optimization of storage options for cost effectiveness and utility impact.

A solar thermal cooling and heating system at Carnegie Mellon University was studied through its design, installation, modeling, and evaluation to deal with the question of how solar energy might most effectively be used in supplying energy for the operation of a building. This solar cooling and heating system incorporates 52 m{sup 2} of linear parabolic trough solar collectors; a 16 kW double effect, water-lithium bromide (LiBr) absorption chiller, and a heat recovery heat exchanger with their circulation pumps and control valves. It generates chilled and heated water, dependent on the season, for space cooling and heating. This system is the smallest high temperature solar cooling system in the world. Till now, only this system of the kind has been successfully operated for more than one year. Performance of the system has been tested and the measured data were used to verify system performance models developed in the TRaNsient SYstem Simulation program (TRNSYS). On the basis of the installed solarsystem, base case performance models were programmed; and then they were modified and extended to investigate measures for improving system performance. The measures included changes in the area and orientation of the solar collectors, the inclusion of thermal storage in the system, changes in the pipe diameter and length, and various system operational control strategies. It was found that this solar thermal system could potentially supply 39% of cooling and 20% of heating energy for this building space in Pittsburgh, PA, if it included a properly sized storage tank and short, low diameter connecting pipes. Guidelines for the design and operation of an efficient and effective solar cooling and heating system for a given building space have been provided. (author)

Prior to commercial operation, large solarsystems in utility-size power plants need to pass a performance acceptance test conducted by the engineering, procurement, and construction (EPC) contractor or owners. In lieu of the present absence of ASME or other international test codes developed for this purpose, the National Renewable Energy Laboratory has undertaken the development of interim guidelines to provide recommendations for test procedures that can yield results of a high level of accuracy consistent with good engineering knowledge and practice. Progress on interim guidelines was presented at SolarPACES 2010. Significant additions and modifications were made to the guidelines since that time, resulting in a final report published by NREL in April 2011. This paper summarizes those changes, which emphasize criteria for assuring thermal equilibrium and steady state conditions within the solar field.

Presented in this paper are innovative concepts to substantially reduce the cost of residential solar application. They were based on a research and development approach that establishes cost goals which if successfully met can insure high marketability. Included in this cost goal-oriented approach is the additional need to address aesthetics and performance. With such constraints established, designs were initialized, tested, and iterated towards appropriate solutions. These solutions are based on methods for reducing the material intensity of the products, improving the simplicity for ease of production, and reducing the cost of installation. Such a development approach has yielded past proof-of-concept designs in the solar collector and in the other components that constitute a total solar heating system.

This paper studied the slab solar collection (SSC) process, which is one of the essential compositions of road hydronic ice-snow melting (HISM) system that stores solar energy in summer to melt ice and snow on the road in winter. Its aim is to find out the heat transfer characteristic of the SSC and heat collecting efficiency and the influence of pipe spacing and flow rate by experiment. As shown in experimental results, the average heat collecting capacity is about 150-250 W/m{sup 2} in natural summer condition, while the solar radiation intensity is about 300-1000 W/m{sup 2}. It is shown that the increment of fluid flow results in the increment of heat collection efficiency, while the increment of pipe spacing results in the decrement of the efficiency in experiment modes. The results show that the road slab can obtain about 30% solar heat in summertime, and the solar collection can lower the pavement temperature and reduce the insolation weathering. (author)

Sandia National Laboratories, Albuquerque (SNLA), is currently conducting a program to predict the performance and measure the characteristics of commercially available solar collectors that have the potential for use in industrial process heat and enhanced oil recovery applications. The thermal performance predictions for the Solar Kinetics T-600 solar line-focusing parabolic trough collector are presented for three output temperatures at five cities in the US. (WHK)

SOLARCITY AND THE HAWAIIAN ELECTRIC COMPANIES NREL is collaborating with solar energy company SolarCity at the ESIF to address the safety, reliability, and stability challenges of interconnecting high penetrations of distributed photovoltaics (PV) with the electric power system. The work includes collaboration with the Hawaiian Electric Companies to analyze high-penetration solar scenarios using advanced modeling and inverter testing at the ESIF. R&D STRATEGY The ESIF's unique megawatt-scale

A sensible heat receiver considered in this study uses a vapor grown carbon fiber-carbon (VGCF/C) composite as the thermal storage media and was designed for a 7 kW Brayton engine. The proposed heat receiver stores the required energy to power the system during eclipse in the VGCF/C composite. The heat receiver thermal analysis was conducted through the Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA) software package. The sensible heat receiver compares well with other latent and advanced sensible heat receivers analyzed in other studies while avoiding the problems associated with latent heat storage salts and liquid metal heat pipes. The concept also satisfies the design requirements for a 7 kW Brayton engine system. The weight and size of the system can be optimized by changes in geometry and technology advances for this new material.

A Photovoltaic Metallization Research Forum, under the sponsorship of the Jet Propulsion Laboratory's Flat-Plate Solar Array Project and the US Department of Energy, was held March 16-18, 1983 at Pine Mountain, Georgia. The Forum consisted of five sessions, covering (1) the current status of metallization systems, (2) system design, (3) thick-film metallization, (4) advanced techniques and (5) future metallization challenges. Twenty-three papers were presented.

Detailed calculations are presented that cover the pressure drops in the pipelines added to the Hidalgo smelting plant due to the solar air system and the addition of a feedwater heater and superheater. A series of calculations is also given that addresses the performance of the flash smelting process. Additional calculations deal with the heat and mass balances for the steam system. Data on an analysis of the gas turbine and a system performance source code are included. Some specific data on power into the solar receiver from the user selected heliostat field are given for 170-meter, 190-meter, and 210-meter towers. Seven major trade areas addressed include: receiver operating pressure and temperature; selection of process heat air temperature; design point receiver power; thermal energy storage subsystem capacity; solar heliostat field optimization; gas turbine configuration and control; and tower height optimization. Analysis of the performance data of the smelting process and thermal analysis data of the cavity solar receiver for the Hidalgo smelter are given. (MCW)

A new method of predicting the solar heat gain through complex fenestration systems involving nonspecular layers such as shades or blinds has been examined in a project jointly sponsored by ASHRAE and DOE. In this method, a scanning radiometer is used to measure the bidirectional radiative transmittance and reflectance of each layer of a fenestration system. The properties of systems containing these layers are then built up computationally from the measured layer properties using a transmission/multiple-reflection calculation. The calculation produces the total directional-hemispherical transmittance of the fenestration system and the layer-by-layer absorbances. These properties are in turn combined with layer-specific measurements of the inward-flowing fractions of absorbed solar energy to produce the overall solar heat gain coefficient. The method has been applied to one of the most optically complex systems in common use, a venetian blind in combination with multiple glazings. A comparison between the scanner-based calculation method and direct system calorimetric measurements made on the LBL MoWiTT facility showed good agreement, and is a significant validation of the method accuracy and feasibility.

A radiative cooling system for use with an ice-making system having a radiating surface aimed at the sky for radiating energy at one or more wavelength bands for which the atmosphere is transparent and a cover thermally isolated from the radiating surface and transparent at least to the selected wavelength or wavelengths, the thermal isolation reducing the formation of condensation on the radiating surface and/or cover and permitting the radiation to continue when the radiating surface is below the dewpoint of the atmosphere, and a housing supporting the radiating surface, cover and heat transfer means to an ice storage reservoir.

A radiative cooling system for use with an ice-making system having a radiating surface aimed at the sky for radiating energy at one or more wavelength bands for which the atmosphere is transparent and a cover thermally isolated from the radiating surface and transparent at least to the selected wavelength or wavelengths, the thermal isolation reducing the formation of condensation on the radiating surface and/or cover and permitting the radiation to continue when the radiating surface is below the dewpoint of the atmosphere, and a housing supporting the radiating surface, cover and heat transfer means to an ice storage reservoir.

The addition of solar thermal and heat storage systems can improve the economic, as well as environmental attraction of micro-generation systems, e.g. fuel cells with or without combined heat and power (CHP) and contribute to enhanced CO2 reduction. However, the interactions between solar thermal collection and storage systems and CHP systems can be complex, depending on the tariff structure, load profile, etc. In order to examine the impact of solar thermal and heat storage on CO2 emissions and annual energy costs, a microgrid's distributed energy resources (DER) adoption problem is formulated as a mixed-integer linear program. The objective is minimization of annual energy costs. This paper focuses on analysis of the optimal interaction of solar thermal systems, which can be used for domestic hot water, space heating and/or cooling, and micro-CHP systems in the California service territory of San Diego Gas and Electric (SDG&E). Contrary to typical expectations, our results indicate that despite the high solar radiation in southern California, fossil based CHP units are dominant, even with forecast 2020 technology and costs. A CO2 pricing scheme would be needed to incent installation of combined solar thermal absorption chiller systems, and no heat storage systems are adopted. This research also shows that photovoltaic (PV) arrays are favored by CO2 pricing more than solar thermal adoption.

Highly efficient direct current (DC) appliances have the potential to dramatically increase the affordability of off-grid solar power systems used for rural electrification in developing countries by reducing the size of the systems required. For example, the combined power requirement of a highly efficient color TV, four DC light emitting diode (LED) lamps, a mobile phone charger, and a radio is approximately 18 watts and can be supported by a small solar power system (at 27 watts peak, Wp). Price declines and efficiency advances in LED technology are already enabling rapidly increased use of small off-grid lighting systems in Africa and Asia. Similar progress is also possible for larger household-scale solar home systems that power appliances such as lights, TVs, fans, radios, and mobile phones. When super-efficient appliances are used, the total cost of solar home systems and their associated appliances can be reduced by as much as 50%. The results vary according to the appliances used with the system. These findings have critical relevance for efforts to provide modern energy services to the 1.2 billion people worldwide without access to the electrical grid and one billion more with unreliable access. However, policy and market support are needed to realize rapid adoption of super-efficient appliances.

In this paper, a methodology for estimating solar potential on multiple building rooftops is presented. The objective of this methodology is to estimate the daily or monthly solar radiation potential on individual buildings in a city/region using Light Detection and Ranging (LiDAR) data and a geographic information system (GIS) approach. Conceptually, the methodology is based on the upward-looking hemispherical viewshed algorithm, but applied using an area-based modeling approach. The methodology considers input parameters, such as surface orientation, shadowing effect, elevation, and atmospheric conditions, that influence solar intensity on the earth s surface. The methodology has been implemented for some 212,000 buildings in Knox County, Tennessee, USA. Based on the results obtained, the methodology seems to be adequate for estimating solar radiation on multiple building rooftops. The use of LiDAR data improves the radiation potential estimates in terms of the model predictive error and the spatial pattern of the model outputs. This methodology could help cities/regions interested in sustainable projects to quickly identify buildings with higher potentials for roof-mounted photovoltaic systems.

The SRRL was established at the Solar Energy Research Institute (now NREL) in 1981 to provide continuous measurements of the solar resources, outdoor calibrations of pyranometers and pyrheliometers, and to characterize commercially available instrumentation. The SRRL is an outdoor laboratory located on South Table Mountain, a mesa providing excellent solar access throughout the year, overlooking Denver. Beginning with the basic measurements of global horizontal irradiance, direct normal irradiance and diffuse horizontal irradiance at 5-minute intervals, the SRRL Baseline Measurement System now produces more than 130 data elements at 1-min intervals that are available from the Measurement & Instrumentation Data Center Web site. Data sources include global horizontal, direct normal, diffuse horizontal (from shadowband and tracking disk), global on tilted surfaces, reflected solar irradiance, ultraviolet, infrared (upwelling and downwelling), photometric and spectral radiometers, sky imagery, and surface meteorological conditions (temperature, relative humidity, barometric pressure, precipitation, snow cover, wind speed and direction at multiple levels). Data quality control and assessment include daily instrument maintenance (M-F) with automated data quality control based on real-time examinations of redundant instrumentation and internal consistency checks using NREL's SERI-QC methodology. Operators are notified of equipment problems by automatic e-mail messages generated by the data acquisition and processing system. Radiometers are recalibrated at least annually with reference instruments traceable to the World Radiometric Reference (WRR).

The SRRL was established at the Solar Energy Research Institute (now NREL) in 1981 to provide continuous measurements of the solar resources, outdoor calibrations of pyranometers and pyrheliometers, and to characterize commercially available instrumentation. The SRRL is an outdoor laboratory located on South Table Mountain, a mesa providing excellent solar access throughout the year, overlooking Denver. Beginning with the basic measurements of global horizontal irradiance, direct normal irradiance and diffuse horizontal irradiance at 5-minute intervals, the SRRL Baseline Measurement System now produces more than 130 data elements at 1-min intervals that are available from the Measurement & Instrumentation Data Center Web site. Data sources include global horizontal, direct normal, diffuse horizontal (from shadowband and tracking disk), global on tilted surfaces, reflected solar irradiance, ultraviolet, infrared (upwelling and downwelling), photometric and spectral radiometers, sky imagery, and surface meteorological conditions (temperature, relative humidity, barometric pressure, precipitation, snow cover, wind speed and direction at multiple levels). Data quality control and assessment include daily instrument maintenance (M-F) with automated data quality control based on real-time examinations of redundant instrumentation and internal consistency checks using NREL's SERI-QC methodology. Operators are notified of equipment problems by automatic e-mail messages generated by the data acquisition and processing system. Radiometers are recalibrated at least annually with reference instruments traceable to the World Radiometric Reference (WRR).

This paper describes the concept for augmenting the SEGIS Program (an industry-led effort to greatly enhance the utility of distributed PV systems) with energy storage in residential and small commercial applications (SEGIS-ES). The goal of SEGIS-ES is to develop electrical energy storage components and systems specifically designed and optimized for grid-tied PV applications. This report describes the scope of the proposed SEGIS-ES Program and why it will be necessary to integrate energy storage with PV systems as PV-generated energy becomes more prevalent on the nation's utility grid. It also discusses the applications for which energy storage is most suited and for which it will provide the greatest economic and operational benefits to customers and utilities. Included is a detailed summary of the various storage technologies available, comparisons of their relative costs and development status, and a summary of key R&D needs for PV-storage systems. The report concludes with highlights of areas where further PV-specific R&D is needed and offers recommendations about how to proceed with their development.

Today, our questions and hypotheses about the SolarSystem's origin have surpassed our ability to deliver scientific instruments to deep space. The moons of the outer planets, the Trojan and Centaur minor planets, the trans-Neptunian objects (TNO), and distant Kuiper Belt objects (KBO) hold a wealth of information about the primordial conditions that led to the formation of our SolarSystem. Robotic missions to these objects are needed to make the discoveries, but the lack of deep-space propulsion is impeding this science. Radioisotope electric propulsion (REP) will revolutionize the way we do deep-space planetary science with robotic vehicles, giving them unprecedented mobility. Radioisotope electric generators and lightweight ion thrusters are being developed today which will make possible REP systems with specific power in the range of 5 to 10 W/kg. Studies have shown that this specific power range is sufficient to perform fast rendezvous missions from Earth to the outer SolarSystem and fast sample return missions. This whitepaper discusses how mobility provided by REP opens up entirely new science opportunities for robotic missions to distant primitive bodies. We also give an overview of REP technology developments and the required next steps to realize REP.

The purpose of these Guidelines is to provide direction for conducting performance acceptance testing for large power tower solarsystems that can yield results of a high level of accuracy consistent with good engineering knowledge and practice. The recommendations have been developed under a National Renewable Energy Laboratory (NREL) subcontract and reviewed by stakeholders representing concerned organizations and interests throughout the concentrating solar power (CSP) community. An earlier NREL report provided similar guidelines for parabolic trough systems. These Guidelines recommend certain methods, instrumentation, equipment operating requirements, and calculation methods. When tests are run in accordance with these Guidelines, we expect that the test results will yield a valid indication of the actual performance of the tested equipment. But these are only recommendations--to be carefully considered by the contractual parties involved in the Acceptance Tests--and we expect that modifications may be required to fit the particular characteristics of a specific project.

In this paper, a transient simulation model of solar-assisted heating and cooling systems (SHC) is presented. A detailed case study is also discussed, in which three different configurations are considered. In all cases, the SHC system is based on the coupling of evacuated solar collectors with a single-stage LiBr-H{sub 2}O absorption chiller, and a gas-fired boiler is also included for auxiliary heating, only during the winter season. In the first configuration, the cooling capacity of the absorption chiller and the solar collector area are designed on the basis of the maximum cooling load, and an electric chiller is used as the auxiliary cooling system. The second layout is similar to the first one, but, in this case, the absorption chiller and the solar collector area are sized in order to balance only a fraction of the maximum cooling load. Finally, in the third configuration, there is no electric chiller, and the auxiliary gas-fired boiler is also used in summer to feed the absorption chiller, in case of scarce solar irradiation. The simulation model was developed using the TRNSYS software, and included the analysis of the dynamic behaviour of the building in which the SHC systems were supposed to be installed. The building was simulated using a single-lumped capacitance model. An economic model was also developed, in order to assess the operating and capital costs of the systems under analysis. Furthermore, a mixed heuristic-deterministic optimization algorithm was implemented, in order to determine the set of the synthesis/design variables that maximize the energy efficiency of each configuration under analysis. The results of the case study were analyzed on monthly and weekly basis, paying special attention to the energy and monetary flows of the standard and optimized configurations. The results are encouraging as for the potential of energy saving. On the contrary, the SHC systems appear still far from the economic profitability: however, this is

There is confusion in the marketplace regarding the impact of solar photovoltaics (PV) on the user's actual electricity bill under California Net Energy Metering, particularly with binomial tariffs (those that include both demand and energy charges) and time-of-use (TOU) rate structures. The City of San Diego has extensive real-time electrical metering on most of its buildings and PV systems, with interval data for overall consumption and PV electrical production available for multiple years. This paper uses 2007 PV-system data from two city facilities to illustrate the impacts of binomial rate designs. The analysis will determine the energy and demand savings that the PV systems are achieving relative to the absence of systems. A financial analysis of PV-system performance under various rate structures is presented. The data revealed that actual demand and energy use benefits of binomial tariffs increase in summer months, when solar resources allow for maximized electricity production. In a binomial tariff system, varying on- and semi-peak times can result in approximately $1,100 change in demand charges per month over not having a PV system in place, an approximate 30% cost savings. The PV systems are also shown to have a 30%-50% reduction in facility energy charges in 2007.

We demonstrated that adding nanoparticles to a molten salt would increase its utility as a thermal energy storage medium for a concentrating solar power system. Specifically, we demonstrated that we could increase the specific heat of nitrate and carbonate salts containing 1% or less of alumina nanoparticles. We fabricated the composite materials using both evaporative and air drying methods. We tested several thermophysical properties of the composite materials, including the specific heat, thermal conductivity, latent heat, and melting point. We also assessed the stability of the composite material with repeated thermal cycling and the effects of adding the nanoparticles on the corrosion of stainless steel by the composite salt. Our results indicate that stable, repeatable 25-50% improvements in specific heat are possible for these materials. We found that using these composite salts as the thermal energy storage material for a concentrating solar thermal power system can reduce the levelized cost of electricity by 10-20%. We conclude that these materials are worth further development and inclusion in future concentrating solar power systems.

A systematic framework is proposed to estimate the impact on operating costs due to uncertainty and variability in renewable resources. The framework quantifies the integration costs associated with subhourly variability and uncertainty as well as day-ahead forecasting errors in solar PV (photovoltaics) power. A case study illustrates how changes in system operations may affect these costs for a utility in the southwestern United States (Arizona Public Service Company). We conduct an extensive sensitivity analysis under different assumptions about balancing reserves, system flexibility, fuel prices, and forecasting errors. We find that high solar PV penetrations may lead to operational challenges, particularly during low-load and high solar periods. Increased system flexibility is essential for minimizing integration costs and maintaining reliability. In a set of sensitivity cases where such flexibility is provided, in part, by flexible operations of nuclear power plants, the estimated integration costs vary between $1.0 and $4.4/MWh-PV for a PV penetration level of 17%. The integration costs are primarily due to higher needs for hour-ahead balancing reserves to address the increased sub-hourly variability and uncertainty in the PV resource. (C) 2015 Elsevier Ltd. All rights reserved.

A comprehensive program was undertaken to develop a unique gas fired backup for solar domestic hot water systems. Detailed computer design tools were written. A series of heat transfer experiments were performed to characterize the performance of individual components. A full scale engineering prototype, including the solar preheat tank and solar heat exchanger, was designed, fabricated and subjected to limited testing. Firing efficiency for the backup system was found to be 81.4% at a firing rate of 50,000 Btu/h. Long term standby losses should be negligible.

This report sets forth the system requirements for a Solar Controlled-Environment Agriculture System (SCEAS) Project. In the report a conceptual baseline system description for an engineering test facility is given. This baseline system employs a fluid roof/roof filter in combination with a large storage tank and a ground water heat exchanger in order to provide cooling and heating as needed. Desalination is accomplished by pretreatment followed by reverse osmosis. Energy is provided by means of photovoltaics and wind machines in conjunction with storage batteries. Site and climatic data needed in the design process are given. System performance specifications and integrated system design criteria are set forth. Detailed subsystem design criteria are presented and appropriate references documented.

Thermosyphon heat exchangers are used in indirect solar water heating systems to avoid using a pump to circulate water from the storage tank to the heat exchanger. In this study, the authors consider the effect of heat exchanger design on system performance. They also compare performance of a system with thermosyphon flow to the same system with a 40W pump in the water loop. In the first part of the study, the authors consider the impact of heat exchanger design on the thermal performance of both one- and two-collector solar water heaters. The comparison is based on Solar Rating and Certification Corporation (SRCC) OG300 simulations. The thermosyphon heat exchangers considered are (1) a one-pass, double wall, 0.22 m{sup 2}, four tube-in-shell heat exchanger manufactured by AAA Service and Supply, Inc., (the Quad-Rod); (2) a two-pass, double wall, 0.2 m{sup 2}, tube-in-shell made by Heliodyne, Inc., but not intended for commercial development; (3) a one-pass, single wall, 0.28 m{sup 2}, 31 tube-in-shell heat exchanger from Young Radiator Company, and (4) a one-pass single-wall, 0.61 m{sup 2}, four coil-in-shell heat exchanger made by ThermoDynamics Ltd. The authors compare performance of the systems with thermosyphon heat exchangers to a system with a 40 W pump used with the Quad-Rod heat exchanger. In the second part of the study, the effects of reducing frictional losses through the heat exchanger and/or the pipes connecting the heat exchanger to the storage tank, and increasing heat transfer area are evaluated in terms of OG300 ratings.

The invention provides a system and method for controlling the storing and elease of thermal energy from a thermal storage wall wherein said wall is capable of storing thermal energy from insolation of solar radiation. The system and method includes a device such as a plurality of louvers spaced a predetermined distance from the thermal wall for regulating the release of thermal energy from the thermal wall. This regulating device is made from a material which is substantially transparent to the incoming solar radiation so that when it is in any operative position, the thermal storage wall substantially receives all of the impacting solar radiation. The material in the regulating device is further capable of being substantially opaque to thermal energy so that when the device is substantially closed, thermal release of energy from the storage wall is substantially minimized. An adjustment device is interconnected with the regulating mechanism for selectively opening and closing it in order to regulate the release of thermal energy from the wall.

This is a report on the feasibility study, design, and construction of a PV and solar thermal system for the Georgia Tech Aquatic Center. The topics of the report include a discussion of site selection and system selection, funding, design alternatives, PV module selection, final design, and project costs. Included are appendices describing the solar thermal system, the SAC entrance canopy PV mockup, and the PV feasibility study.

An analytic method for calculating the optimum operating temperature of the collector/storage subsystem in a solar assisted heat pump is presented. A tradeoff exists between rising heat pump coefficient of performance and falling collector efficiency as this temperature is increased, resulting in an optimum temperature whose value increases with increasing efficiency of the auxiliary energy source. Electric resistance is shown to be a poor backup to such systems. A number of options for thermally coupling the system to the ground are analyzed and compared.

This annual report presents work performed during calendar year 1993 by the Florida Solar Energy Center under contract to the US Department of Energy. Two distinctively different solar powered indoor climate control systems were analyzed: the open cycle liquid desiccant dehumidifier, and an improved efficiency absorption system which may be fired by flat plate solar collectors. Both tasks represent new directions relative to prior FSEC research in Solar Cooling and Dehumidification.

A conceptual design of a sodium-cooled, solar, central-receiver repowering system for West Texas Utilities' Paint Creek Unit 4 was prepared, solely under funds provided by West Texas Utilities (WTU), the Energy Systems Group (ESG) of Rockwell International, and four other support groups. A central-receiver repowering system is one in which a tower, surrounded by a large field of mirrors, is placed adjacent to an existing electric power plant. A receiver, located on top of the tower, absorbs solar energy reflected onto it by the mirrors and converts this solar energy to heat energy. The heat energy is transported by the liquid sodium to a set of sodium-to-steam steam generators. The steam generators produce steam at the same temperature and pressure as that produced by the fossil boiler in the existing plant. When solar energy is available, steam is produced by the solar part of the plant, thus displacing steam from the fossil boiler, and reducing the consumption of fossil fuel while maintaining the original plant output. A means for storing the solar energy is usually provided, so that some energy obtained from the solar source can be used to displace natural gas or oil fuels when the sun is not shining. This volume presents an executive summary of the conceptual design, performance, economics, development plans, and site owner's assessment. (WHK)

The University of Pennsylvania SolaRow house, an urban row home retrofitted for comfort and domestic hot water heating, was extensively instrumented for performance monitoring and acquisition of weather and solar radiation data. This report describes the heating and instrumentation systems, provides the details for instrumentation, piping and valve identification, and specifies the operation and maintenance of the heating and data acquisition systems. The following are included: (1) system flow diagrams; (2) valve and cable identification tables; (3) wiring diagrams; and (4) start-up, normal operation, shut-down, maintenance and trouble-shooting procedures. It thus provides the necessary technical information to permit system operation and monitoring, overall system performance analysis and optimization, and acquisition of climatological data.

A rating method for solar domestic hot water (SDHW) systems is presented that provides site-specific annual performance estimates based on ASHRAE-95 test results. An overall loss and overall gain coefficient are estimated by lumping the entire thermal behavior of the actual system exhibited during the ASHRAE-95 test into the collector parameters of a simplified system model. The performance of the simplified model can then be predicted using either the F-chart or TRNSYS and presented as an estimate of the annual performance of the actual system. Experimental performance measurements taken from relevant literature as well as extensive simulations, indicate that this method is capable of predicting the annual performance of a wide range of SDHW system types to within 5%, independent of location.

Community Solar Community solar, also known as shared solar or solar gardens, is a solar energy deployment model that allows customers to buy or lease part of an offsite shared solar PV system. This arrangement lets customers enjoy advantages of solar energy without having to install a system on their own residential or commercial property. Community solar projects provide distributed solar access and benefits to customers who: Have insufficient solar resources (e.g. shading, roof size, etc.) Do

Dish-Stirling solar receiver designs are investigated and evaluated for possible use with sensible energy storage in single-phase materials. The designs differ from previous receivers in utilizing axial conduction in the storage material for attenuation of the solar flux transients due to intermittent cloud cover, and in having convective heat removal at the base of the receiver. One-dimensional, time-dependent heat transfer equations are formulated for the storage material temperature field, including losses to the environment, and a general heat exchange effectiveness boundary condition at the base. The solar source flux is represented as the sum of steady and periodic cloud-transient components, with the steady component solved subject to specified receiver thermal efficiency. For the transient cloud-cover component the Fast Fourier Transform algorithm (FFT) is applied, and the complex transfer function of the receiver is obtained as a filter for the input flux spectrum. Inverse transformation results in the amplitudes and mode shapes of the transient temperature component. By adjustment of design parameters, the cloud-cover amplitude variations of the outlet gas temperature can be limited to acceptable magnitudes, thus simplifying control systems.

During the last three years under the sponsorship of the DOE Solar Passive Division, the University of Dayton Research Institute (UDRI) has investigated four phase change material (PCM) systems for utility in thermal energy storage for solar passive heating and cooling applications. From this research on the basis of cost, performance, containment, and environmental acceptability, we have selected as our current and most promising series of candidate phase change materials, C-15 to C-24 linear crystalline alkyl hydrocarbons. The major part of the research during this contract period was directed toward the following three objectives. Find, test, and develop low-cost effective phase change materials (PCM) that melt and freeze sharply in the comfort temperature range of 73--77{degree}F for use in solar passive heating and cooling of buildings. Define practical materials and processes for fire retarding plasterboard/PCM building products. Develop cost-effective methods for incorporating PCM into building construction materials (concrete, plasterboard, etc.) which will lead to the commercial manufacture and sale of PCM-containing products resulting in significant energy conservation.

Unified Solar is an MIT startup that is commercializing an integrated circuit solution that eliminates most of the adverse effects caused by partial shading in photovoltaic power systems. With its patent-pending design, Unified Solar's solution is smaller, cheaper and more powerful than any competing power optimizer in the market.

Accurate determination of the luminous and thermal performance of fenestration systems that incorporate optically complex components requires detailed knowledge of their radiant behavior. We describe a large scanning radiometer used to measure the bidirectional transmittance and reflectance of fenestration systems and components. We present examples of measured data obtained for simple non-specular samples. We describe a method of obtaining the overall properties of fenestration systems by calculation from scanning radiometer measurements of fenestration components. Finally, we describe the application of bidirectional solar-optical properties of fenestration systems to determine their luminous and thermal performance with respect to building energy consumption and occupants' comfort. We also discuss the advantages and limitations of the method, which appears to be promising.

Prior to commercial operation, large solarsystems in utility-size power plants need to pass a performance acceptance test conducted by the engineering, procurement, and construction (EPC) contractor or owners. In lieu of the present absence of ASME or other international test codes developed for this purpose, the National Renewable Energy Laboratory has undertaken the development of interim guidelines to provide recommendations for test procedures that can yield results of a high level of accuracy consistent with good engineering knowledge and practice. The Guidelines contained here are specifically written for parabolic trough collector systems with a heat-transport system using a high-temperature synthetic oil, but the basic principles are relevant to other CSP systems.

Sandia National Laboratories, Albuquerque (SNLA), is currently conducting a program to predict the performance and measure the characteristics of commercially available solar collectors that have the potential for use in industrial process heat and enhanced oil recovery applications. The thermal performance predictions for the Sun-Heet nontracking, line-focusing parabolic trough collector at five cities in the US are presented. (WHK)

Utilities are overseeing the installations of thousand of solar hot water (SHW) systems. Utility planners have begun to ask for quantitative measures of the expected lifetimes of these systems so that they can properly forecast their loads. This report, which augments a 2009 reliability analysis effort by Sandia National Laboratories (SNL), addresses this need. Additional reliability data have been collected, added to the existing database, and analyzed. The results are presented. Additionally, formal reliability theory is described, including the bathtub curve, which is the most common model to characterize the lifetime reliability character of systems, and for predicting failures in the field. Reliability theory is used to assess the SNL reliability database. This assessment shows that the database is heavily weighted with data that describe the reliability of SHW systems early in their lives, during the warranty period. But it contains few measured data to describe the ends of SHW systems lives. End-of-life data are the most critical ones to define sufficiently the reliability of SHW systems in order to answer the questions that the utilities pose. Several ideas are presented for collecting the required data, including photometric analysis of aerial photographs of installed collectors, statistical and neural network analysis of energy bills from solar homes, and the development of simple algorithms to allow conventional SHW controllers to announce system failures and record the details of the event, similar to how aircraft black box recorders perform. Some information is also presented about public expectations for the longevity of a SHW system, information that is useful in developing reliability goals.

A cavity central receiver hybrid solar cogeneration retrofit for a smelting facility producing copper and sulfuric acid is described. Existing facilities and the southwest New Mexico site are described. The process for selection of the system configuration and subsystem criteria is described. This process involves the use of performance analyses, cost estimates, economic trade-offs, and vendor quotations and consultation. An air-based central receiver was selected, and sensible heat storage in rock is considered. A discounted cash flow analysis based upon the results of the conceptual design performance and cost estimates is performed. (LEW)

An hourly simulation program has been developed for detailed modelin of an evaporation surface (ES) and an evaporation pond (EP) for reconcentration of a solar pond's (SP's) surface brine. The results are relavant to other systems in which it is desirable to concentrate a brine. The simulation results are used in three ways: first, for general comparison of brine reconcentration performance for a variety of locations; second, development of an ES design method based on long term monthly averaged weather data; and third, an economic comparison between ESs and EPs. The results show that regions with moderate to high precipitation favor ESs over EPs. Dry climates will generally favor EPs for brine reconcentration.

This Best Practices in Commercial and Industrial Solar Photovoltaic System Installation Guide is the second of a series of guides designed to standardize and improve solar asset transparency for investors and rating agencies, provide an industry framework for quality management, and reduce transaction costs in the solar asset securitization process. The Best Practices in C&I PV System Installation Guide is intended to outline the minimum requirements for commercial and industrial solar project developments. Adherence to the guide is voluntary. Providers that adhere to the guide are responsible for self-certifying that they have fulfilled the guide requirements. Investors and rating agencies should verify compliance.